81564452 has 12 divisors (see below), whose sum is σ = 142817136. Its totient is φ = 40759560.

The previous prime is 81564451. The next prime is 81564467. The reversal of 81564452 is 25446518.

It is not an unprimeable number, because it can be changed into a prime (81564451) 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, 4427 + ... + 13517.

It is an arithmetic number, because the mean of its divisors is an integer number (11901428).

Almost surely, 2^81564452 is an apocalyptic number.

It is an amenable number.

81564452 is a deficient number, since it is larger than the sum of its proper divisors (61252684).

81564452 is a wasteful number, since it uses less digits than its factorization.

81564452 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11338 (or 11336 counting only the distinct ones).

The product of its digits is 38400, while the sum is 35.

The square root of 81564452 is about 9031.3040032987. The cubic root of 81564452 is about 433.6775833836.

The spelling of 81564452 in words is "eighty-one million, five hundred sixty-four thousand, four hundred fifty-two".