990386931 has 16 divisors (see below), whose sum is σ = 1333928960. Its totient is φ = 653585760.

The previous prime is 990386893. The next prime is 990386953. The reversal of 990386931 is 139683099.

It is a happy number.

990386931 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-990386931 is a prime.

It is a super-2 number, since 2×990386931² = 1961732546191197522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (990386531) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 117000 + ... + 125178.

It is an arithmetic number, because the mean of its divisors is an integer number (83370560).

Almost surely, 2^990386931 is an apocalyptic number.

990386931 is a deficient number, since it is larger than the sum of its proper divisors (343542029).

990386931 is a wasteful number, since it uses less digits than its factorization.

990386931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8586.

The product of its (nonzero) digits is 314928, while the sum is 48.

The square root of 990386931 is about 31470.4135816484. The cubic root of 990386931 is about 996.7853205765.

The spelling of 990386931 in words is "nine hundred ninety million, three hundred eighty-six thousand, nine hundred thirty-one".