1616561000 has 64 divisors (see below), whose sum is σ = 3844910160. Its totient is φ = 636000000.

The previous prime is 1616560987. The next prime is 1616561027. The reversal of 1616561000 is 1656161.

It can be written as a sum of positive squares in 8 ways, for example, as 64673764 + 1551887236 = 8042^2 + 39394^2 .

It is a super-2 number, since 2×1616561000² = 5226538933442000000, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47750 + ... + 74250.

Almost surely, 2^1616561000 is an apocalyptic number.

1616561000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1616561000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1922455080).

1616561000 is an abundant number, since it is smaller than the sum of its proper divisors (2228349160).

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

1616561000 is a wasteful number, since it uses less digits than its factorization.

1616561000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26583 (or 26569 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 1616561000 is about 40206.4795773020. The cubic root of 1616561000 is about 1173.6286400156.

The spelling of 1616561000 in words is "one billion, six hundred sixteen million, five hundred sixty-one thousand".