991117403925 has 96 divisors (see below), whose sum is σ = 1803807775104. Its totient is φ = 480163622400.

The previous prime is 991117403911. The next prime is 991117403959. The reversal of 991117403925 is 529304711199.

It is not a de Polignac number, because 991117403925 - 2⁸ = 991117403669 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 159417417 + ... + 159423633.

It is an arithmetic number, because the mean of its divisors is an integer number (18789664324).

Almost surely, 2^991117403925 is an apocalyptic number.

It is an amenable number.

991117403925 is a deficient number, since it is larger than the sum of its proper divisors (812690371179).

991117403925 is a wasteful number, since it uses less digits than its factorization.

991117403925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7860 (or 7833 counting only the distinct ones).

The product of its (nonzero) digits is 612360, while the sum is 51.

The spelling of 991117403925 in words is "nine hundred ninety-one billion, one hundred seventeen million, four hundred three thousand, nine hundred twenty-five".