81445692 has 12 divisors (see below), whose sum is σ = 190039976. Its totient is φ = 27148560.

The previous prime is 81445687. The next prime is 81445699. The reversal of 81445692 is 29654418.

It is a tau number, because it is divible by the number of its divisors (12).

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 81445692.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81445699) 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, 3393559 + ... + 3393582.

Almost surely, 2^81445692 is an apocalyptic number.

It is an amenable number.

81445692 is an abundant number, since it is smaller than the sum of its proper divisors (108594284).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81445692 is a wasteful number, since it uses less digits than its factorization.

81445692 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6787148 (or 6787146 counting only the distinct ones).

The product of its digits is 69120, while the sum is 39.

The square root of 81445692 is about 9024.7266994630. The cubic root of 81445692 is about 433.4669991334.

The spelling of 81445692 in words is "eighty-one million, four hundred forty-five thousand, six hundred ninety-two".