2015861980 has 24 divisors (see below), whose sum is σ = 4618157040. Its totient is φ = 733040640.

The previous prime is 2015861951. The next prime is 2015861999. The reversal of 2015861980 is 891685102.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4581285 + ... + 4581724.

It is an arithmetic number, because the mean of its divisors is an integer number (192423210).

Almost surely, 2^2015861980 is an apocalyptic number.

2015861980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2015861980 is an abundant number, since it is smaller than the sum of its proper divisors (2602295060).

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

2015861980 is a wasteful number, since it uses less digits than its factorization.

2015861980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9163029 (or 9163027 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 40.

The square root of 2015861980 is about 44898.3516401215. The cubic root of 2015861980 is about 1263.2430900390.

The spelling of 2015861980 in words is "two billion, fifteen million, eight hundred sixty-one thousand, nine hundred eighty".