81850992 has 80 divisors (see below), whose sum is σ = 220938240. Its totient is φ = 26078976.

The previous prime is 81850991. The next prime is 81850999. The reversal of 81850992 is 29905818.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81850991) 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, 176553 + ... + 177015.

It is an arithmetic number, because the mean of its divisors is an integer number (2761728).

Almost surely, 2^81850992 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 81850992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110469120).

81850992 is an abundant number, since it is smaller than the sum of its proper divisors (139087248).

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

81850992 is a wasteful number, since it uses less digits than its factorization.

81850992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 630 (or 624 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 42.

The square root of 81850992 is about 9047.1538065847. The cubic root of 81850992 is about 434.1848335296.

The spelling of 81850992 in words is "eighty-one million, eight hundred fifty thousand, nine hundred ninety-two".