261534263432520 has 128 divisors (see below), whose sum is σ = 845126785036800. Its totient is φ = 64364717497344.

The previous prime is 261534263432467. The next prime is 261534263432543. The reversal of 261534263432520 is 25234362435162.

It is a self number, because there is not a number n which added to its sum of digits gives 261534263432520.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9098160 + ... + 24613919.

It is an arithmetic number, because the mean of its divisors is an integer number (6602553008100).

Almost surely, 2^{261534263432520} is an apocalyptic number.

261534263432520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261534263432520 is an abundant number, since it is smaller than the sum of its proper divisors (583592521604280).

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

261534263432520 is a wasteful number, since it uses less digits than its factorization.

261534263432520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33717079 (or 33717075 counting only the distinct ones).

The product of its (nonzero) digits is 6220800, while the sum is 48.

The spelling of 261534263432520 in words is "two hundred sixty-one trillion, five hundred thirty-four billion, two hundred sixty-three million, four hundred thirty-two thousand, five hundred twenty".