81369492 has 48 divisors (see below), whose sum is σ = 199946880. Its totient is φ = 25704448.

The previous prime is 81369487. The next prime is 81369493. The reversal of 81369492 is 29496318.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81369493) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 29884 + ... + 32492.

It is an arithmetic number, because the mean of its divisors is an integer number (4165560).

Almost surely, 2^81369492 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 81369492, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99973440).

81369492 is an abundant number, since it is smaller than the sum of its proper divisors (118577388).

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

81369492 is a wasteful number, since it uses less digits than its factorization.

81369492 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2752 (or 2750 counting only the distinct ones).

The product of its digits is 93312, while the sum is 42.

The square root of 81369492 is about 9020.5039770514. The cubic root of 81369492 is about 433.3317740904.

The spelling of 81369492 in words is "eighty-one million, three hundred sixty-nine thousand, four hundred ninety-two".