261421121132670 has 16 divisors (see below), whose sum is σ = 627410690718480. Its totient is φ = 69712298968704.

The previous prime is 261421121132629. The next prime is 261421121132681. The reversal of 261421121132670 is 76231121124162.

It is a happy number.

It is a Curzon number.

It is a congruent number.

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, 4357018685515 + ... + 4357018685574.

It is an arithmetic number, because the mean of its divisors is an integer number (39213168169905).

Almost surely, 2^{261421121132670} is an apocalyptic number.

261421121132670 is an abundant number, since it is smaller than the sum of its proper divisors (365989569585810).

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

261421121132670 is a wasteful number, since it uses less digits than its factorization.

261421121132670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8714037371099.

The product of its (nonzero) digits is 48384, while the sum is 39.

The spelling of 261421121132670 in words is "two hundred sixty-one trillion, four hundred twenty-one billion, one hundred twenty-one million, one hundred thirty-two thousand, six hundred seventy".