81607523 has 4 divisors (see below), whose sum is σ = 81925320. Its totient is φ = 81289728.

The previous prime is 81607517. The next prime is 81607549. The reversal of 81607523 is 32570618.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81607523 - 2¹² = 81603427 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81607523.

It is not an unprimeable number, because it can be changed into a prime (81607423) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 158513 + ... + 159026.

It is an arithmetic number, because the mean of its divisors is an integer number (20481330).

Almost surely, 2^81607523 is an apocalyptic number.

81607523 is a deficient number, since it is larger than the sum of its proper divisors (317797).

81607523 is a wasteful number, since it uses less digits than its factorization.

81607523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317796.

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

The square root of 81607523 is about 9033.6882279609. The cubic root of 81607523 is about 433.7539060128.

The spelling of 81607523 in words is "eighty-one million, six hundred seven thousand, five hundred twenty-three".