81406800 has 90 divisors (see below), whose sum is σ = 282516702. Its totient is φ = 21707520.

The previous prime is 81406789. The next prime is 81406813. The reversal of 81406800 is 860418.

It can be written as a sum of positive squares in 3 ways, for example, as 3825936 + 77580864 = 1956^2 + 8808^2 .

It is a tau number, because it is divible by the number of its divisors (90).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 7707 + ... + 14906.

Almost surely, 2^81406800 is an apocalyptic number.

81406800 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81406800 is an abundant number, since it is smaller than the sum of its proper divisors (201109902).

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

81406800 is a wasteful number, since it uses less digits than its factorization.

81406800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22637 (or 22623 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 81406800 is about 9022.5716954757. The cubic root of 81406800 is about 433.3979916667.

The spelling of 81406800 in words is "eighty-one million, four hundred six thousand, eight hundred".