81299692 has 6 divisors (see below), whose sum is σ = 142274468. Its totient is φ = 40649844.

The previous prime is 81299633. The next prime is 81299741. The reversal of 81299692 is 29699218.

It is a super-5 number, since 5×81299692⁵ (a number of 41 digits) contains 55555 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10162458 + ... + 10162465.

Almost surely, 2^81299692 is an apocalyptic number.

It is an amenable number.

81299692 is a deficient number, since it is larger than the sum of its proper divisors (60974776).

81299692 is a wasteful number, since it uses less digits than its factorization.

81299692 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20324927 (or 20324925 counting only the distinct ones).

The product of its digits is 139968, while the sum is 46.

The square root of 81299692 is about 9016.6341835521. The cubic root of 81299692 is about 433.2078324268.

The spelling of 81299692 in words is "eighty-one million, two hundred ninety-nine thousand, six hundred ninety-two".