81880872 has 16 divisors (see below), whose sum is σ = 204702240. Its totient is φ = 27293616.

The previous prime is 81880867. The next prime is 81880873. The reversal of 81880872 is 27808818.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (81880873) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1705828 + ... + 1705875.

It is an arithmetic number, because the mean of its divisors is an integer number (12793890).

Almost surely, 2^81880872 is an apocalyptic number.

It is an amenable number.

81880872 is an abundant number, since it is smaller than the sum of its proper divisors (122821368).

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

81880872 is a wasteful number, since it uses less digits than its factorization.

81880872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3411712 (or 3411708 counting only the distinct ones).

The product of its (nonzero) digits is 57344, while the sum is 42.

The square root of 81880872 is about 9048.8050039770. The cubic root of 81880872 is about 434.2376606820.

The spelling of 81880872 in words is "eighty-one million, eight hundred eighty thousand, eight hundred seventy-two".