261421167011540 has 48 divisors (see below), whose sum is σ = 566998139334144. Its totient is φ = 101140913174400.

The previous prime is 261421167011533. The next prime is 261421167011561. The reversal of 261421167011540 is 45110761124162.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 112131254 + ... + 114438893.

It is an arithmetic number, because the mean of its divisors is an integer number (11812461236128).

Almost surely, 2^{261421167011540} is an apocalyptic number.

261421167011540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261421167011540 is an abundant number, since it is smaller than the sum of its proper divisors (305576972322604).

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

261421167011540 is a wasteful number, since it uses less digits than its factorization.

261421167011540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226572048 (or 226572046 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 41.

The spelling of 261421167011540 in words is "two hundred sixty-one trillion, four hundred twenty-one billion, one hundred sixty-seven million, eleven thousand, five hundred forty".