81930774529 has 4 divisors (see below), whose sum is σ = 81931863600. Its totient is φ = 81929685460.

The previous prime is 81930774517. The next prime is 81930774533. The reversal of 81930774529 is 92547703918.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81930774529 - 2²³ = 81922385921 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81930774529.

It is not an unprimeable number, because it can be changed into a prime (81930774599) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 422587 + ... + 585184.

It is an arithmetic number, because the mean of its divisors is an integer number (20482965900).

Almost surely, 2^81930774529 is an apocalyptic number.

It is an amenable number.

81930774529 is a deficient number, since it is larger than the sum of its proper divisors (1089071).

81930774529 is a wasteful number, since it uses less digits than its factorization.

81930774529 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1089070.

The product of its (nonzero) digits is 3810240, while the sum is 55.

The spelling of 81930774529 in words is "eighty-one billion, nine hundred thirty million, seven hundred seventy-four thousand, five hundred twenty-nine".