991604872 has 32 divisors (see below), whose sum is σ = 1912579200. Its totient is φ = 481737024.

The previous prime is 991604869. The next prime is 991604879. The reversal of 991604872 is 278406199.

It is not an unprimeable number, because it can be changed into a prime (991604879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42778 + ... + 61750.

It is an arithmetic number, because the mean of its divisors is an integer number (59768100).

Almost surely, 2^991604872 is an apocalyptic number.

It is an amenable number.

991604872 is a deficient number, since it is larger than the sum of its proper divisors (920974328).

991604872 is a wasteful number, since it uses less digits than its factorization.

991604872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19165 (or 19161 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 46.

The square root of 991604872 is about 31489.7582080269. The cubic root of 991604872 is about 997.1937563630.

The spelling of 991604872 in words is "nine hundred ninety-one million, six hundred four thousand, eight hundred seventy-two".