72218646479 has 4 divisors (see below), whose sum is σ = 82535595984. Its totient is φ = 61901696976.

The previous prime is 72218646449. The next prime is 72218646499. The reversal of 72218646479 is 97464681227.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97464681227 = 41 ⋅2377187347.

It is not a de Polignac number, because 72218646479 - 2⁸ = 72218646223 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 (72218646449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5158474742 + ... + 5158474755.

It is an arithmetic number, because the mean of its divisors is an integer number (20633898996).

Almost surely, 2^72218646479 is an apocalyptic number.

72218646479 is a deficient number, since it is larger than the sum of its proper divisors (10316949505).

72218646479 is a wasteful number, since it uses less digits than its factorization.

72218646479 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10316949504.

The product of its digits is 8128512, while the sum is 56.

The spelling of 72218646479 in words is "seventy-two billion, two hundred eighteen million, six hundred forty-six thousand, four hundred seventy-nine".