81653552 has 20 divisors (see below), whose sum is σ = 159256176. Its totient is φ = 40555200.

The previous prime is 81653521. The next prime is 81653557. The reversal of 81653552 is 25535618.

It is not an unprimeable number, because it can be changed into a prime (81653557) 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, 14483 + ... + 19314.

Almost surely, 2^81653552 is an apocalyptic number.

It is an amenable number.

81653552 is a deficient number, since it is larger than the sum of its proper divisors (77602624).

81653552 is a wasteful number, since it uses less digits than its factorization.

81653552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33956 (or 33950 counting only the distinct ones).

The product of its digits is 36000, while the sum is 35.

The square root of 81653552 is about 9036.2354993659. The cubic root of 81653552 is about 433.8354405958.

The spelling of 81653552 in words is "eighty-one million, six hundred fifty-three thousand, five hundred fifty-two".