81022913 has 2 divisors, whose sum is σ = 81022914. Its totient is φ = 81022912.

The previous prime is 81022873. The next prime is 81022937. The reversal of 81022913 is 31922018.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74787904 + 6235009 = 8648^2 + 2497^2 .

It is a cyclic number.

It is not a de Polignac number, because 81022913 - 2¹⁸ = 80760769 is a prime.

It is not a weakly prime, because it can be changed into another prime (81022943) 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 as a sum of consecutive naturals, namely, 40511456 + 40511457.

It is an arithmetic number, because the mean of its divisors is an integer number (40511457).

Almost surely, 2^81022913 is an apocalyptic number.

It is an amenable number.

81022913 is a deficient number, since it is larger than the sum of its proper divisors (1).

81022913 is an equidigital number, since it uses as much as digits as its factorization.

81022913 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 81022913 is about 9001.2728544356. The cubic root of 81022913 is about 432.7156651032.

The spelling of 81022913 in words is "eighty-one million, twenty-two thousand, nine hundred thirteen".