81429792 has 24 divisors (see below), whose sum is σ = 213753456. Its totient is φ = 27143232.

The previous prime is 81429791. The next prime is 81429793. The reversal of 81429792 is 29792418.

It is an interprime number because it is at equal distance from previous prime (81429791) and next prime (81429793).

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×81429792² = 13261622050326528, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81429791) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 424018 + ... + 424209.

It is an arithmetic number, because the mean of its divisors is an integer number (8906394).

Almost surely, 2^81429792 is an apocalyptic number.

It is an amenable number.

81429792 is an abundant number, since it is smaller than the sum of its proper divisors (132323664).

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

81429792 is a wasteful number, since it uses less digits than its factorization.

81429792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 848240 (or 848232 counting only the distinct ones).

The product of its digits is 72576, while the sum is 42.

The square root of 81429792 is about 9023.8457433624. The cubic root of 81429792 is about 433.4387898500.

The spelling of 81429792 in words is "eighty-one million, four hundred twenty-nine thousand, seven hundred ninety-two".