81633652 has 18 divisors (see below), whose sum is σ = 150776178. Its totient is φ = 38667888.

The previous prime is 81633649. The next prime is 81633667. The reversal of 81633652 is 25633618.

It can be written as a sum of positive squares in only one way, i.e., 47831056 + 33802596 = 6916^2 + 5814^2 .

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 26823 + ... + 29710.

Almost surely, 2^81633652 is an apocalyptic number.

It is an amenable number.

81633652 is a deficient number, since it is larger than the sum of its proper divisors (69142526).

81633652 is a wasteful number, since it uses less digits than its factorization.

81633652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56575 (or 56554 counting only the distinct ones).

The product of its digits is 25920, while the sum is 34.

The square root of 81633652 is about 9035.1343100144. The cubic root of 81633652 is about 433.8001940102.

Subtracting from 81633652 its sum of digits (34), we obtain a palindrome (81633618).

The spelling of 81633652 in words is "eighty-one million, six hundred thirty-three thousand, six hundred fifty-two".