72821235815 has 4 divisors (see below), whose sum is σ = 87385482984. Its totient is φ = 58256988648.

The previous prime is 72821235803. The next prime is 72821235829. The reversal of 72821235815 is 51853212827.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51853212827 = 13 ⋅3988708679.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72821235815 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7282123577 + ... + 7282123586.

It is an arithmetic number, because the mean of its divisors is an integer number (21846370746).

Almost surely, 2^72821235815 is an apocalyptic number.

72821235815 is a deficient number, since it is larger than the sum of its proper divisors (14564247169).

72821235815 is a wasteful number, since it uses less digits than its factorization.

72821235815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14564247168.

The product of its digits is 268800, while the sum is 44.

The spelling of 72821235815 in words is "seventy-two billion, eight hundred twenty-one million, two hundred thirty-five thousand, eight hundred fifteen".