81623243 has 8 divisors (see below), whose sum is σ = 88494000. Its totient is φ = 74837088.

The previous prime is 81623203. The next prime is 81623249. The reversal of 81623243 is 34232618.

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

It is a cyclic number.

It is not a de Polignac number, because 81623243 - 2²⁰ = 80574667 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81623249) 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, 19133 + ... + 23006.

It is an arithmetic number, because the mean of its divisors is an integer number (11061750).

Almost surely, 2^81623243 is an apocalyptic number.

81623243 is a deficient number, since it is larger than the sum of its proper divisors (6870757).

81623243 is a wasteful number, since it uses less digits than its factorization.

81623243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42301.

The product of its digits is 6912, while the sum is 29.

The square root of 81623243 is about 9034.5582625826. The cubic root of 81623243 is about 433.7817554617.

The spelling of 81623243 in words is "eighty-one million, six hundred twenty-three thousand, two hundred forty-three".