81925280 has 48 divisors (see below), whose sum is σ = 197220744. Its totient is φ = 32148480.

The previous prime is 81925279. The next prime is 81925303. The reversal of 81925280 is 8252918.

It can be written as a sum of positive squares in 4 ways, for example, as 45104656 + 36820624 = 6716^2 + 6068^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81925280.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3650 + ... + 13310.

Almost surely, 2^81925280 is an apocalyptic number.

81925280 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81925280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98610372).

81925280 is an abundant number, since it is smaller than the sum of its proper divisors (115295464).

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

81925280 is a wasteful number, since it uses less digits than its factorization.

81925280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9729 (or 9721 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 81925280 is about 9051.2584760353. The cubic root of 81925280 is about 434.3161492653.

The spelling of 81925280 in words is "eighty-one million, nine hundred twenty-five thousand, two hundred eighty".