81599401579 has 2 divisors, whose sum is σ = 81599401580. Its totient is φ = 81599401578.

The previous prime is 81599401573. The next prime is 81599401627. The reversal of 81599401579 is 97510499518.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81599401579 - 2²¹ = 81597304427 is a prime.

It is not a weakly prime, because it can be changed into another prime (81599401573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40799700789 + 40799700790.

It is an arithmetic number, because the mean of its divisors is an integer number (40799700790).

Almost surely, 2^81599401579 is an apocalyptic number.

81599401579 is a deficient number, since it is larger than the sum of its proper divisors (1).

81599401579 is an equidigital number, since it uses as much as digits as its factorization.

81599401579 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4082400, while the sum is 58.

The spelling of 81599401579 in words is "eighty-one billion, five hundred ninety-nine million, four hundred one thousand, five hundred seventy-nine".