991261534504624 has 40 divisors (see below), whose sum is σ = 1921302881982000. Its totient is φ = 495441449001216.

The previous prime is 991261534504607. The next prime is 991261534504639. The reversal of 991261534504624 is 426405435162199.

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, 1259040562 + ... + 1259827630.

It is an arithmetic number, because the mean of its divisors is an integer number (48032572049550).

Almost surely, 2^{991261534504624} is an apocalyptic number.

It is an amenable number.

991261534504624 is a deficient number, since it is larger than the sum of its proper divisors (930041347477376).

991261534504624 is a wasteful number, since it uses less digits than its factorization.

991261534504624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 817045 (or 817039 counting only the distinct ones).

The product of its (nonzero) digits is 55987200, while the sum is 61.

The spelling of 991261534504624 in words is "nine hundred ninety-one trillion, two hundred sixty-one billion, five hundred thirty-four million, five hundred four thousand, six hundred twenty-four".