990990431 has 2 divisors, whose sum is σ = 990990432. Its totient is φ = 990990430.

The previous prime is 990990383. The next prime is 990990433. The reversal of 990990431 is 134099099.

990990431 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-990990431 is a prime.

It is a super-2 number, since 2×990990431² = 1964124068667131522, which contains 22 as substring.

Together with 990990433, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (990990433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495495215 + 495495216.

It is an arithmetic number, because the mean of its divisors is an integer number (495495216).

Almost surely, 2^990990431 is an apocalyptic number.

990990431 is a deficient number, since it is larger than the sum of its proper divisors (1).

990990431 is an equidigital number, since it uses as much as digits as its factorization.

990990431 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 78732, while the sum is 44.

The square root of 990990431 is about 31480.0004923761. Note that the first 3 decimals coincide. The cubic root of 990990431 is about 996.9877457685.

The spelling of 990990431 in words is "nine hundred ninety million, nine hundred ninety thousand, four hundred thirty-one".