81894600 has 72 divisors (see below), whose sum is σ = 275035410. Its totient is φ = 21838080.

The previous prime is 81894599. The next prime is 81894611. The reversal of 81894600 is 649818.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 46539684 + 35354916 = 6822^2 + 5946^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 20949 + ... + 24548.

Almost surely, 2^81894600 is an apocalyptic number.

It is an amenable number.

81894600 is an abundant number, since it is smaller than the sum of its proper divisors (193140810).

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

81894600 is a wasteful number, since it uses less digits than its factorization.

81894600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45519 (or 45507 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 81894600 is about 9049.5635253862. The cubic root of 81894600 is about 434.2619271614.

The spelling of 81894600 in words is "eighty-one million, eight hundred ninety-four thousand, six hundred".