81375732 has 48 divisors (see below), whose sum is σ = 211612800. Its totient is φ = 27043200.

The previous prime is 81375731. The next prime is 81375733. The reversal of 81375732 is 23757318.

81375732 is a `hidden beast` number, since 81 + 3 + 7 + 573 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (81375731) and next prime (81375733).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81375731) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42369 + ... + 44247.

It is an arithmetic number, because the mean of its divisors is an integer number (4408600).

Almost surely, 2^81375732 is an apocalyptic number.

It is an amenable number.

81375732 is an abundant number, since it is smaller than the sum of its proper divisors (130237068).

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

81375732 is a wasteful number, since it uses less digits than its factorization.

81375732 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2293 (or 2285 counting only the distinct ones).

The product of its digits is 35280, while the sum is 36.

The square root of 81375732 is about 9020.8498490996. The cubic root of 81375732 is about 433.3428508100.

The spelling of 81375732 in words is "eighty-one million, three hundred seventy-five thousand, seven hundred thirty-two".