81952620291 has 8 divisors (see below), whose sum is σ = 121411289360. Its totient is φ = 54635080176.

The previous prime is 81952620283. The next prime is 81952620301. The reversal of 81952620291 is 19202625918.

It is a happy number.

81952620291 is a `hidden beast` number, since 8 + 19 + 5 + 2 + 620 + 2 + 9 + 1 = 666.

It is not a de Polignac number, because 81952620291 - 2³ = 81952620283 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81952220291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1517641090 + ... + 1517641143.

It is an arithmetic number, because the mean of its divisors is an integer number (15176411170).

Almost surely, 2^81952620291 is an apocalyptic number.

81952620291 is a deficient number, since it is larger than the sum of its proper divisors (39458669069).

81952620291 is a wasteful number, since it uses less digits than its factorization.

81952620291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3035282242 (or 3035282236 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 45.

The spelling of 81952620291 in words is "eighty-one billion, nine hundred fifty-two million, six hundred twenty thousand, two hundred ninety-one".