81864250 has 32 divisors (see below), whose sum is σ = 165044880. Its totient is φ = 30225600.

The previous prime is 81864229. The next prime is 81864253. The reversal of 81864250 is 5246818.

It can be written as a sum of positive squares in 8 ways, for example, as 6365529 + 75498721 = 2523^2 + 8689^2 .

It is not an unprimeable number, because it can be changed into a prime (81864253) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9345 + ... + 15844.

Almost surely, 2^81864250 is an apocalyptic number.

81864250 is an abundant number, since it is smaller than the sum of its proper divisors (83180630).

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

81864250 is a wasteful number, since it uses less digits than its factorization.

81864250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25219 (or 25209 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 34.

The square root of 81864250 is about 9047.8864935409. The cubic root of 81864250 is about 434.2082749549.

The spelling of 81864250 in words is "eighty-one million, eight hundred sixty-four thousand, two hundred fifty".