81428466 has 16 divisors (see below), whose sum is σ = 186122304. Its totient is φ = 23265264.

The previous prime is 81428407. The next prime is 81428467. The reversal of 81428466 is 66482418.

It is a super-2 number, since 2×81428466² = 13261190150226312, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81428467) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 969345 + ... + 969428.

It is an arithmetic number, because the mean of its divisors is an integer number (11632644).

Almost surely, 2^81428466 is an apocalyptic number.

81428466 is an abundant number, since it is smaller than the sum of its proper divisors (104693838).

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

81428466 is a wasteful number, since it uses less digits than its factorization.

81428466 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1938785.

The product of its digits is 73728, while the sum is 39.

The square root of 81428466 is about 9023.7722710627. The cubic root of 81428466 is about 433.4364371363.

The spelling of 81428466 in words is "eighty-one million, four hundred twenty-eight thousand, four hundred sixty-six".