72536643491 has 8 divisors (see below), whose sum is σ = 78240191904. Its totient is φ = 66850781760.

The previous prime is 72536643479. The next prime is 72536643497. The reversal of 72536643491 is 19434663527.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72536643491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72536643497) 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, 4413146 + ... + 4429551.

It is an arithmetic number, because the mean of its divisors is an integer number (9780023988).

Almost surely, 2^72536643491 is an apocalyptic number.

72536643491 is a deficient number, since it is larger than the sum of its proper divisors (5703548413).

72536643491 is a wasteful number, since it uses less digits than its factorization.

72536643491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8843341.

The product of its digits is 3265920, while the sum is 50.

The spelling of 72536643491 in words is "seventy-two billion, five hundred thirty-six million, six hundred forty-three thousand, four hundred ninety-one".