81889392 has 80 divisors (see below), whose sum is σ = 239845760. Its totient is φ = 23867136.

The previous prime is 81889387. The next prime is 81889397. The reversal of 81889392 is 29398818.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81889387) and next prime (81889397).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81889397) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8403 + ... + 15309.

It is an arithmetic number, because the mean of its divisors is an integer number (2998072).

Almost surely, 2^81889392 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 81889392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119922880).

81889392 is an abundant number, since it is smaller than the sum of its proper divisors (157956368).

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

81889392 is a wasteful number, since it uses less digits than its factorization.

81889392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6950 (or 6944 counting only the distinct ones).

The product of its digits is 248832, while the sum is 48.

The square root of 81889392 is about 9049.2757721267. The cubic root of 81889392 is about 434.2527214911.

The spelling of 81889392 in words is "eighty-one million, eight hundred eighty-nine thousand, three hundred ninety-two".