81672530 has 8 divisors (see below), whose sum is σ = 147010572. Its totient is φ = 32669008.

The previous prime is 81672529. The next prime is 81672571. The reversal of 81672530 is 3527618.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 81558961 + 113569 = 9031^2 + 337^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4083617 + ... + 4083636.

Almost surely, 2^81672530 is an apocalyptic number.

81672530 is a deficient number, since it is larger than the sum of its proper divisors (65338042).

81672530 is a wasteful number, since it uses less digits than its factorization.

81672530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8167260.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 81672530 is about 9037.2855437902. The cubic root of 81672530 is about 433.8690488141.

The spelling of 81672530 in words is "eighty-one million, six hundred seventy-two thousand, five hundred thirty".