90640031 has 2 divisors, whose sum is σ = 90640032. Its totient is φ = 90640030.

The previous prime is 90639947. The next prime is 90640049. The reversal of 90640031 is 13004609.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90640031 is a prime.

It is a super-2 number, since 2×90640031² = 16431230439361922, which contains 22 as substring.

It is a Sophie Germain prime.

It is equal to p_5252018 and since 90640031 and 5252018 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 90639979 and 90640006.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90640061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45320015 + 45320016.

It is an arithmetic number, because the mean of its divisors is an integer number (45320016).

Almost surely, 2^90640031 is an apocalyptic number.

90640031 is a deficient number, since it is larger than the sum of its proper divisors (1).

90640031 is an equidigital number, since it uses as much as digits as its factorization.

90640031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 90640031 is about 9520.5058163944. The cubic root of 90640031 is about 449.2002767228.

The spelling of 90640031 in words is "ninety million, six hundred forty thousand, thirty-one".