81749232 has 60 divisors (see below), whose sum is σ = 236177344. Its totient is φ = 26369280.

The previous prime is 81749197. The next prime is 81749249. The reversal of 81749232 is 23294718.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4693 + ... + 13620.

Almost surely, 2^81749232 is an apocalyptic number.

It is an amenable number.

81749232 is an abundant number, since it is smaller than the sum of its proper divisors (154428112).

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

81749232 is a wasteful number, since it uses less digits than its factorization.

81749232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18358 (or 18349 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 81749232 is about 9041.5281894158. The cubic root of 81749232 is about 434.0048276838.

The spelling of 81749232 in words is "eighty-one million, seven hundred forty-nine thousand, two hundred thirty-two".