261621757160 has 16 divisors (see below), whose sum is σ = 588648953700. Its totient is φ = 104648702848.

The previous prime is 261621757141. The next prime is 261621757171. The reversal of 261621757160 is 61757126162.

It can be written as a sum of positive squares in 2 ways, for example, as 258838772644 + 2782984516 = 508762^2 + 52754^2 .

It is a super-2 number, since 2×261621757160² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3270271925 + ... + 3270272004.

Almost surely, 2^261621757160 is an apocalyptic number.

261621757160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261621757160 is an abundant number, since it is smaller than the sum of its proper divisors (327027196540).

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

261621757160 is a wasteful number, since it uses less digits than its factorization.

261621757160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6540543940 (or 6540543936 counting only the distinct ones).

The product of its (nonzero) digits is 211680, while the sum is 44.

The spelling of 261621757160 in words is "two hundred sixty-one billion, six hundred twenty-one million, seven hundred fifty-seven thousand, one hundred sixty".