81744800 has 36 divisors (see below), whose sum is σ = 199561446. Its totient is φ = 32697600.

The previous prime is 81744787. The next prime is 81744811. The reversal of 81744800 is 844718.

It can be written as a sum of positive squares in 3 ways, for example, as 34904464 + 46840336 = 5908^2 + 6844^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 50291 + ... + 51890.

Almost surely, 2^81744800 is an apocalyptic number.

81744800 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81744800 is an abundant number, since it is smaller than the sum of its proper divisors (117816646).

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

81744800 is a wasteful number, since it uses less digits than its factorization.

81744800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102201 (or 102188 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 81744800 is about 9041.2830947825. The cubic root of 81744800 is about 433.9969844128.

The spelling of 81744800 in words is "eighty-one million, seven hundred forty-four thousand, eight hundred".