81598894651 has 2 divisors, whose sum is σ = 81598894652. Its totient is φ = 81598894650.

The previous prime is 81598894633. The next prime is 81598894687. The reversal of 81598894651 is 15649889518.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81598894651 - 2⁷ = 81598894523 is a prime.

It is not a weakly prime, because it can be changed into another prime (81598894631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40799447325 + 40799447326.

It is an arithmetic number, because the mean of its divisors is an integer number (40799447326).

Almost surely, 2^81598894651 is an apocalyptic number.

81598894651 is a deficient number, since it is larger than the sum of its proper divisors (1).

81598894651 is an equidigital number, since it uses as much as digits as its factorization.

81598894651 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24883200, while the sum is 64.

The spelling of 81598894651 in words is "eighty-one billion, five hundred ninety-eight million, eight hundred ninety-four thousand, six hundred fifty-one".