1639990431 has 6 divisors (see below), whose sum is σ = 2368875080. Its totient is φ = 1093326948.

The previous prime is 1639990381. The next prime is 1639990463. The reversal of 1639990431 is 1340999361.

1639990431 is a `hidden beast` number, since 1 + 639 + 9 + 9 + 0 + 4 + 3 + 1 = 666.

It is not a de Polignac number, because 1639990431 - 2⁹ = 1639989919 is a prime.

It is a super-2 number, since 2×1639990431² = 5379137227543131522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1639990481) 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 5 ways as a sum of consecutive naturals, for example, 91110571 + ... + 91110588.

Almost surely, 2^1639990431 is an apocalyptic number.

1639990431 is a deficient number, since it is larger than the sum of its proper divisors (728884649).

1639990431 is a wasteful number, since it uses less digits than its factorization.

1639990431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182221165 (or 182221162 counting only the distinct ones).

The product of its (nonzero) digits is 157464, while the sum is 45.

The square root of 1639990431 is about 40496.7953176545. The cubic root of 1639990431 is about 1179.2714143981.

The spelling of 1639990431 in words is "one billion, six hundred thirty-nine million, nine hundred ninety thousand, four hundred thirty-one".