72186433621 has 4 divisors (see below), whose sum is σ = 72233832672. Its totient is φ = 72139034572.

The previous prime is 72186433559. The next prime is 72186433637. The reversal of 72186433621 is 12633468127.

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 not a de Polignac number, because 72186433621 - 2²³ = 72178045013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72186433021) 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, 23697241 + ... + 23700286.

It is an arithmetic number, because the mean of its divisors is an integer number (18058458168).

Almost surely, 2^72186433621 is an apocalyptic number.

It is an amenable number.

72186433621 is a deficient number, since it is larger than the sum of its proper divisors (47399051).

72186433621 is a wasteful number, since it uses less digits than its factorization.

72186433621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47399050.

The product of its digits is 290304, while the sum is 43.

The spelling of 72186433621 in words is "seventy-two billion, one hundred eighty-six million, four hundred thirty-three thousand, six hundred twenty-one".