1661601000 has 64 divisors (see below), whose sum is σ = 5184204480. Its totient is φ = 443092800.

The previous prime is 1661600981. The next prime is 1661601041. The reversal of 1661601000 is 1061661.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 273934 + ... + 279933.

It is an arithmetic number, because the mean of its divisors is an integer number (81003195).

Almost surely, 2^1661601000 is an apocalyptic number.

1661601000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1661601000 is an abundant number, since it is smaller than the sum of its proper divisors (3522603480).

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

1661601000 is a wasteful number, since it uses less digits than its factorization.

1661601000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 553891 (or 553877 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 1661601000 is about 40762.7403396779. The cubic root of 1661601000 is about 1184.4286800694.

Adding to 1661601000 its reverse (1061661), we get a palindrome (1662662661).

The spelling of 1661601000 in words is "one billion, six hundred sixty-one million, six hundred one thousand".