81862686 has 48 divisors (see below), whose sum is σ = 180694800. Its totient is φ = 26782080.

The previous prime is 81862663. The next prime is 81862699. The reversal of 81862686 is 68626818.

81862686 is a `hidden beast` number, since 8 + 18 + 626 + 8 + 6 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 351226 + ... + 351458.

It is an arithmetic number, because the mean of its divisors is an integer number (3764475).

Almost surely, 2^81862686 is an apocalyptic number.

81862686 is an abundant number, since it is smaller than the sum of its proper divisors (98832114).

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

81862686 is a wasteful number, since it uses less digits than its factorization.

81862686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521 (or 518 counting only the distinct ones).

The product of its digits is 221184, while the sum is 45.

The square root of 81862686 is about 9047.8000641040. The cubic root of 81862686 is about 434.2055097834.

It can be divided in two parts, 818 and 62686, that added together give a square (63504 = 252²).

The spelling of 81862686 in words is "eighty-one million, eight hundred sixty-two thousand, six hundred eighty-six".