72435581 has 4 divisors (see below), whose sum is σ = 76248000. Its totient is φ = 68623164.

The previous prime is 72435569. The next prime is 72435611. The reversal of 72435581 is 18553427.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72435581 is a prime.

It is a super-2 number, since 2×72435581² = 10493826789615122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72435551) 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, 1906181 + ... + 1906218.

It is an arithmetic number, because the mean of its divisors is an integer number (19062000).

Almost surely, 2^72435581 is an apocalyptic number.

It is an amenable number.

72435581 is a deficient number, since it is larger than the sum of its proper divisors (3812419).

72435581 is a wasteful number, since it uses less digits than its factorization.

72435581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3812418.

The product of its digits is 33600, while the sum is 35.

The square root of 72435581 is about 8510.9095283642. The cubic root of 72435581 is about 416.8540090519.

The spelling of 72435581 in words is "seventy-two million, four hundred thirty-five thousand, five hundred eighty-one".