81535723 has 8 divisors (see below), whose sum is σ = 86434128. Its totient is φ = 76648704.

The previous prime is 81535693. The next prime is 81535763. The reversal of 81535723 is 32753518.

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 81535723 - 2⁵ = 81535691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81535763) 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, 15240 + ... + 19882.

It is an arithmetic number, because the mean of its divisors is an integer number (10804266).

Almost surely, 2^81535723 is an apocalyptic number.

81535723 is a deficient number, since it is larger than the sum of its proper divisors (4898405).

81535723 is a wasteful number, since it uses less digits than its factorization.

81535723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5693.

The product of its digits is 25200, while the sum is 34.

The square root of 81535723 is about 9029.7133398575. The cubic root of 81535723 is about 433.6266601113.

The spelling of 81535723 in words is "eighty-one million, five hundred thirty-five thousand, seven hundred twenty-three".