81654736 has 20 divisors (see below), whose sum is σ = 160114752. Its totient is φ = 40334816.

The previous prime is 81654733. The next prime is 81654737. The reversal of 81654736 is 63745618.

It is a happy number.

It is a super-2 number, since 2×81654736² = 13334991822459392, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81654731) 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, 29416 + ... + 32071.

Almost surely, 2^81654736 is an apocalyptic number.

It is an amenable number.

81654736 is a deficient number, since it is larger than the sum of its proper divisors (78460016).

81654736 is a wasteful number, since it uses less digits than its factorization.

81654736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61578 (or 61572 counting only the distinct ones).

The product of its digits is 120960, while the sum is 40.

The square root of 81654736 is about 9036.3010131359. The cubic root of 81654736 is about 433.8375374985.

The spelling of 81654736 in words is "eighty-one million, six hundred fifty-four thousand, seven hundred thirty-six".