81693804 has 24 divisors (see below), whose sum is σ = 196768768. Its totient is φ = 26352720.

The previous prime is 81693803. The next prime is 81693811. The reversal of 81693804 is 40839618.

It is a super-2 number, since 2×81693804² = 13347755223980832, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81693803) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 109432 + ... + 110175.

Almost surely, 2^81693804 is an apocalyptic number.

It is an amenable number.

81693804 is an abundant number, since it is smaller than the sum of its proper divisors (115074964).

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

81693804 is a wasteful number, since it uses less digits than its factorization.

81693804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219645 (or 219643 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 39.

The square root of 81693804 is about 9038.4624798690. The cubic root of 81693804 is about 433.9067168396.

The spelling of 81693804 in words is "eighty-one million, six hundred ninety-three thousand, eight hundred four".