81698296664 has 32 divisors (see below), whose sum is σ = 157464415200. Its totient is φ = 39709751040.

The previous prime is 81698296651. The next prime is 81698296699. The reversal of 81698296664 is 46669289618.

It is a super-2 number, since 2×81698296664² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81698296664.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 211949 + ... + 456419.

It is an arithmetic number, because the mean of its divisors is an integer number (4920762975).

Almost surely, 2^81698296664 is an apocalyptic number.

It is an amenable number.

81698296664 is a deficient number, since it is larger than the sum of its proper divisors (75766118536).

81698296664 is a wasteful number, since it uses less digits than its factorization.

81698296664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245643 (or 245639 counting only the distinct ones).

The product of its digits is 53747712, while the sum is 65.

The spelling of 81698296664 in words is "eighty-one billion, six hundred ninety-eight million, two hundred ninety-six thousand, six hundred sixty-four".