81047532 has 24 divisors (see below), whose sum is σ = 189259056. Its totient is φ = 26994688.

The previous prime is 81047531. The next prime is 81047537. The reversal of 81047532 is 23574018.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 81047532.

It is not an unprimeable number, because it can be changed into a prime (81047531) 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, 24268 + ... + 27404.

It is an arithmetic number, because the mean of its divisors is an integer number (7885794).

Almost surely, 2^81047532 is an apocalyptic number.

It is an amenable number.

81047532 is an abundant number, since it is smaller than the sum of its proper divisors (108211524).

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

81047532 is a wasteful number, since it uses less digits than its factorization.

81047532 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5297 (or 5295 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 81047532 is about 9002.6402793847. The cubic root of 81047532 is about 432.7594878844.

The spelling of 81047532 in words is "eighty-one million, forty-seven thousand, five hundred thirty-two".