81428694 has 32 divisors (see below), whose sum is σ = 175806720. Its totient is φ = 25066272.

The previous prime is 81428663. The next prime is 81428719. The reversal of 81428694 is 49682418.

It is a Curzon number.

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, 6172 + ... + 14175.

It is an arithmetic number, because the mean of its divisors is an integer number (5493960).

Almost surely, 2^81428694 is an apocalyptic number.

81428694 is an abundant number, since it is smaller than the sum of its proper divisors (94378026).

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

81428694 is a wasteful number, since it uses less digits than its factorization.

81428694 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20404.

The product of its digits is 110592, while the sum is 42.

The square root of 81428694 is about 9023.7849043514. The cubic root of 81428694 is about 433.4368416772.

It can be divided in two parts, 8142 and 8694, that added together give a triangular number (16836 = T₁₈₃).

The spelling of 81428694 in words is "eighty-one million, four hundred twenty-eight thousand, six hundred ninety-four".