261631505698 has 16 divisors (see below), whose sum is σ = 393638178816. Its totient is φ = 130419273600.

The previous prime is 261631505689. The next prime is 261631505701. The reversal of 261631505698 is 896505136162.

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, 943090 + ... + 1188562.

It is an arithmetic number, because the mean of its divisors is an integer number (24602386176).

Almost surely, 2^261631505698 is an apocalyptic number.

261631505698 is a deficient number, since it is larger than the sum of its proper divisors (132006673118).

261631505698 is a wasteful number, since it uses less digits than its factorization.

261631505698 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247089.

The product of its (nonzero) digits is 2332800, while the sum is 52.

The spelling of 261631505698 in words is "two hundred sixty-one billion, six hundred thirty-one million, five hundred five thousand, six hundred ninety-eight".