81630290939 has 2 divisors, whose sum is σ = 81630290940. Its totient is φ = 81630290938.

The previous prime is 81630290873. The next prime is 81630291031. The reversal of 81630290939 is 93909203618.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81630290939 - 2³² = 77335323643 is a prime.

It is not a weakly prime, because it can be changed into another prime (81630290839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40815145469 + 40815145470.

It is an arithmetic number, because the mean of its divisors is an integer number (40815145470).

Almost surely, 2^81630290939 is an apocalyptic number.

81630290939 is a deficient number, since it is larger than the sum of its proper divisors (1).

81630290939 is an equidigital number, since it uses as much as digits as its factorization.

81630290939 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 629856, while the sum is 50.

The spelling of 81630290939 in words is "eighty-one billion, six hundred thirty million, two hundred ninety thousand, nine hundred thirty-nine".