81767238 has 16 divisors (see below), whose sum is σ = 186896640. Its totient is φ = 23362056.

The previous prime is 81767207. The next prime is 81767249. The reversal of 81767238 is 83276718.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 1946839 = 81767238 / (8 + 1 + 7 + 6 + 7 + 2 + 3 + 8).

It is a self number, because there is not a number n which added to its sum of digits gives 81767238.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 973378 + ... + 973461.

It is an arithmetic number, because the mean of its divisors is an integer number (11681040).

Almost surely, 2^81767238 is an apocalyptic number.

81767238 is an abundant number, since it is smaller than the sum of its proper divisors (105129402).

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

81767238 is a wasteful number, since it uses less digits than its factorization.

81767238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1946851.

The product of its digits is 112896, while the sum is 42.

The square root of 81767238 is about 9042.5238733442. The cubic root of 81767238 is about 434.0366898272.

The spelling of 81767238 in words is "eighty-one million, seven hundred sixty-seven thousand, two hundred thirty-eight".