990691839 has 12 divisors (see below), whose sum is σ = 1431333072. Its totient is φ = 660307200.

The previous prime is 990691771. The next prime is 990691843. The reversal of 990691839 is 938196099.

It is not a de Polignac number, because 990691839 - 2²⁷ = 856474111 is a prime.

It is a super-2 number, since 2×990691839² = 1962940639722403842, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (990691879) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38854 + ... + 59084.

It is an arithmetic number, because the mean of its divisors is an integer number (119277756).

Almost surely, 2^990691839 is an apocalyptic number.

990691839 is a deficient number, since it is larger than the sum of its proper divisors (440641233).

990691839 is a wasteful number, since it uses less digits than its factorization.

990691839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25678 (or 25675 counting only the distinct ones).

The product of its (nonzero) digits is 944784, while the sum is 54.

The square root of 990691839 is about 31475.2575684457. The cubic root of 990691839 is about 996.8876026997.

The spelling of 990691839 in words is "nine hundred ninety million, six hundred ninety-one thousand, eight hundred thirty-nine".