261672646120520 has 32 divisors (see below), whose sum is σ = 592513539478200. Its totient is φ = 104002376544768.

The previous prime is 261672646120513. The next prime is 261672646120573. The reversal of 261672646120520 is 25021646276162.

It can be written as a sum of positive squares in 4 ways, for example, as 112512394838596 + 149160251281924 = 10607186^2 + 12213118^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20833803125 + ... + 20833815684.

Almost surely, 2^{261672646120520} is an apocalyptic number.

261672646120520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261672646120520 is an abundant number, since it is smaller than the sum of its proper divisors (330840893357680).

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

261672646120520 is a wasteful number, since it uses less digits than its factorization.

261672646120520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41667618977 (or 41667618973 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 50.

The spelling of 261672646120520 in words is "two hundred sixty-one trillion, six hundred seventy-two billion, six hundred forty-six million, one hundred twenty thousand, five hundred twenty".