81407592 has 160 divisors (see below), whose sum is σ = 264496320. Its totient is φ = 22913280.

The previous prime is 81407569. The next prime is 81407621. The reversal of 81407592 is 29570418.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 594148 + ... + 594284.

It is an arithmetic number, because the mean of its divisors is an integer number (1653102).

Almost surely, 2^81407592 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81407592, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132248160).

81407592 is an abundant number, since it is smaller than the sum of its proper divisors (183088728).

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

81407592 is a wasteful number, since it uses less digits than its factorization.

81407592 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 293 (or 280 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 81407592 is about 9022.6155852945. The cubic root of 81407592 is about 433.3993971598.

The spelling of 81407592 in words is "eighty-one million, four hundred seven thousand, five hundred ninety-two".