81432250 has 16 divisors (see below), whose sum is σ = 152441640. Its totient is φ = 32572800.

The previous prime is 81432229. The next prime is 81432251. The reversal of 81432250 is 5223418.

It can be written as a sum of positive squares in 4 ways, for example, as 34468641 + 46963609 = 5871^2 + 6853^2 .

It is a super-2 number, since 2×81432250² = 13262422680125000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (81432251) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 162615 + ... + 163114.

Almost surely, 2^81432250 is an apocalyptic number.

81432250 is a deficient number, since it is larger than the sum of its proper divisors (71009390).

81432250 is a wasteful number, since it uses less digits than its factorization.

81432250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325746 (or 325736 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 81432250 is about 9023.9819370387. The cubic root of 81432250 is about 433.4431509968.

Adding to 81432250 its reverse (5223418), we get a palindrome (86655668).

The spelling of 81432250 in words is "eighty-one million, four hundred thirty-two thousand, two hundred fifty".