261651799406 has 32 divisors (see below), whose sum is σ = 430601453568. Its totient is φ = 118705115520.

The previous prime is 261651799391. The next prime is 261651799463. The reversal of 261651799406 is 604997156162.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 194750 + ... + 749153.

It is an arithmetic number, because the mean of its divisors is an integer number (13456295424).

Almost surely, 2^261651799406 is an apocalyptic number.

261651799406 is a deficient number, since it is larger than the sum of its proper divisors (168949654162).

261651799406 is a wasteful number, since it uses less digits than its factorization.

261651799406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 944216.

The product of its (nonzero) digits is 4898880, while the sum is 56.

The spelling of 261651799406 in words is "two hundred sixty-one billion, six hundred fifty-one million, seven hundred ninety-nine thousand, four hundred six".