81778032 has 80 divisors (see below), whose sum is σ = 268276480. Its totient is φ = 23364288.

The previous prime is 81778001. The next prime is 81778043. The reversal of 81778032 is 23087718.

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 15 ways as a sum of consecutive naturals, for example, 10498 + ... + 16545.

It is an arithmetic number, because the mean of its divisors is an integer number (3353456).

Almost surely, 2^81778032 is an apocalyptic number.

It is an amenable number.

81778032 is an abundant number, since it is smaller than the sum of its proper divisors (186498448).

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

81778032 is a wasteful number, since it uses less digits than its factorization.

81778032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27067 (or 27055 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 81778032 is about 9043.1207002893. The cubic root of 81778032 is about 434.0557878833.

The spelling of 81778032 in words is "eighty-one million, seven hundred seventy-eight thousand, thirty-two".