81264880 has 40 divisors (see below), whose sum is σ = 192969792. Its totient is φ = 31812864.

The previous prime is 81264877. The next prime is 81264893. The reversal of 81264880 is 8846218.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is a congruent number.

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, 7047 + ... + 14566.

Almost surely, 2^81264880 is an apocalyptic number.

81264880 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81264880 is an abundant number, since it is smaller than the sum of its proper divisors (111704912).

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

81264880 is a wasteful number, since it uses less digits than its factorization.

81264880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21673 (or 21667 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 37.

The square root of 81264880 is about 9014.7035447651. The cubic root of 81264880 is about 433.1459913394.

The spelling of 81264880 in words is "eighty-one million, two hundred sixty-four thousand, eight hundred eighty".