1681000000 has 147 divisors (see below), whose sum is σ = 4273792951. Its totient is φ = 656000000.

The previous prime is 1680999973. The next prime is 1681000019. The reversal of 1681000000 is 1861.

The square root of 1681000000 is 41000.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 10 ways, for example, as 506430016 + 1174569984 = 22504^2 + 34272^2 .

It is a super-2 number, since 2×1681000000² = 5651522000000000000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 40999980 + ... + 41000020.

Almost surely, 2^1681000000 is an apocalyptic number.

1681000000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1681000000 is the 41000-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1681000000

1681000000 is an abundant number, since it is smaller than the sum of its proper divisors (2592792951).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1681000000 is an frugal number, since it uses more digits than its factorization.

1681000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124 (or 48 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 16.

The cubic root of 1681000000 is about 1189.0202136873.

Multiplying 1681000000 by its sum of digits (16), we get a square (26896000000 = 164000²).

1681000000 divided by its sum of digits (16) gives a square (105062500 = 10250²).

Adding to 1681000000 its reverse (1861), we get a palindrome (1681001861).

It can be divided in two parts, 16 and 81000000, that multiplied together give a square (1296000000 = 36000²).

The spelling of 1681000000 in words is "one billion, six hundred eighty-one million", and thus it is an aban number.