81724232 has 16 divisors (see below), whose sum is σ = 153632700. Its totient is φ = 40755520.

The previous prime is 81724229. The next prime is 81724243. The reversal of 81724232 is 23242718.

It can be written as a sum of positive squares in 2 ways, for example, as 63457156 + 18267076 = 7966^2 + 4274^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81724195 and 81724204.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10019 + ... + 16242.

Almost surely, 2^81724232 is an apocalyptic number.

It is an amenable number.

81724232 is a deficient number, since it is larger than the sum of its proper divisors (71908468).

81724232 is a wasteful number, since it uses less digits than its factorization.

81724232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26656 (or 26652 counting only the distinct ones).

The product of its digits is 5376, while the sum is 29.

The square root of 81724232 is about 9040.1455740491. The cubic root of 81724232 is about 433.9605816946.

The spelling of 81724232 in words is "eighty-one million, seven hundred twenty-four thousand, two hundred thirty-two".