81892980 has 144 divisors (see below), whose sum is σ = 271514880. Its totient is φ = 19858176.

The previous prime is 81892973. The next prime is 81892991. The reversal of 81892980 is 8929818.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

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 47 ways as a sum of consecutive naturals, for example, 184639 + ... + 185081.

It is an arithmetic number, because the mean of its divisors is an integer number (1885520).

Almost surely, 2^81892980 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 81892980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135757440).

81892980 is an abundant number, since it is smaller than the sum of its proper divisors (189621900).

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

81892980 is a wasteful number, since it uses less digits than its factorization.

81892980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 550 (or 545 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 45.

The square root of 81892980 is about 9049.4740178642. The cubic root of 81892980 is about 434.2590636883.

The spelling of 81892980 in words is "eighty-one million, eight hundred ninety-two thousand, nine hundred eighty".