261421131207072 has 96 divisors (see below), whose sum is σ = 744318845069184. Its totient is φ = 80014119526400.

The previous prime is 261421131207059. The next prime is 261421131207077. The reversal of 261421131207072 is 270702131124162.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-3 number, since 3×261421131207072³ (a number of 44 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 261421131207072.

It is not an unprimeable number, because it can be changed into a prime (261421131207077) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 1953402804 + ... + 1953536627.

It is an arithmetic number, because the mean of its divisors is an integer number (7753321302804).

Almost surely, 2^{261421131207072} is an apocalyptic number.

It is an amenable number.

261421131207072 is an abundant number, since it is smaller than the sum of its proper divisors (482897713862112).

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

261421131207072 is a wasteful number, since it uses less digits than its factorization.

261421131207072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3906939502 (or 3906939494 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 39.

The spelling of 261421131207072 in words is "two hundred sixty-one trillion, four hundred twenty-one billion, one hundred thirty-one million, two hundred seven thousand, seventy-two".