261631235442 has 16 divisors (see below), whose sum is σ = 523337660352. Its totient is φ = 87197880240.

The previous prime is 261631235413. The next prime is 261631235447. The reversal of 261631235442 is 244532136162.

It is a self number, because there is not a number n which added to its sum of digits gives 261631235442.

It is not an unprimeable number, because it can be changed into a prime (261631235447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3087609 + ... + 3171212.

It is an arithmetic number, because the mean of its divisors is an integer number (32708603772).

Almost surely, 2^261631235442 is an apocalyptic number.

261631235442 is an abundant number, since it is smaller than the sum of its proper divisors (261706424910).

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

261631235442 is a wasteful number, since it uses less digits than its factorization.

261631235442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6265793.

The product of its digits is 207360, while the sum is 39.

The spelling of 261631235442 in words is "two hundred sixty-one billion, six hundred thirty-one million, two hundred thirty-five thousand, four hundred forty-two".