81524993 has 8 divisors (see below), whose sum is σ = 89066496. Its totient is φ = 74005200.

The previous prime is 81524981. The next prime is 81524999. The reversal of 81524993 is 39942518.

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 81524993 - 2⁴ = 81524977 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 81524993.

It is not an unprimeable number, because it can be changed into a prime (81524999) 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, 3008 + ... + 13118.

It is an arithmetic number, because the mean of its divisors is an integer number (11133312).

Almost surely, 2^81524993 is an apocalyptic number.

It is an amenable number.

81524993 is a deficient number, since it is larger than the sum of its proper divisors (7541503).

81524993 is a wasteful number, since it uses less digits than its factorization.

81524993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10855.

The product of its digits is 77760, while the sum is 41.

The square root of 81524993 is about 9029.1191707719. The cubic root of 81524993 is about 433.6076377000.

The spelling of 81524993 in words is "eighty-one million, five hundred twenty-four thousand, nine hundred ninety-three".