81490392 has 96 divisors (see below), whose sum is σ = 235872000. Its totient is φ = 25341120.

The previous prime is 81490369. The next prime is 81490393. The reversal of 81490392 is 29309418.

81490392 is a `hidden beast` number, since 81 + 490 + 3 + 92 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81490393) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 96709 + ... + 97547.

It is an arithmetic number, because the mean of its divisors is an integer number (2457000).

Almost surely, 2^81490392 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 81490392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117936000).

81490392 is an abundant number, since it is smaller than the sum of its proper divisors (154381608).

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

81490392 is a wasteful number, since it uses less digits than its factorization.

81490392 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 941 (or 934 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 81490392 is about 9027.2028890460. The cubic root of 81490392 is about 433.5462848135.

81490392 divided by its sum of digits (36) gives a palindrome (2263622).

The spelling of 81490392 in words is "eighty-one million, four hundred ninety thousand, three hundred ninety-two".