81874428 has 24 divisors (see below), whose sum is σ = 191186688. Its totient is φ = 27270576.

The previous prime is 81874381. The next prime is 81874459. The reversal of 81874428 is 82447818.

It is a self number, because there is not a number n which added to its sum of digits gives 81874428.

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, 29175 + ... + 31857.

It is an arithmetic number, because the mean of its divisors is an integer number (7966112).

Almost surely, 2^81874428 is an apocalyptic number.

It is an amenable number.

81874428 is an abundant number, since it is smaller than the sum of its proper divisors (109312260).

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

81874428 is a wasteful number, since it uses less digits than its factorization.

81874428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5233 (or 5231 counting only the distinct ones).

The product of its digits is 114688, while the sum is 42.

The square root of 81874428 is about 9048.4489278550. The cubic root of 81874428 is about 434.2262689253.

The spelling of 81874428 in words is "eighty-one million, eight hundred seventy-four thousand, four hundred twenty-eight".