72642561517 has 4 divisors (see below), whose sum is σ = 72646247740. Its totient is φ = 72638875296.

The previous prime is 72642561503. The next prime is 72642561527. The reversal of 72642561517 is 71516524627.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71516524627 = 190921 ⋅374587.

It can be written as a sum of positive squares in 2 ways, for example, as 14462227081 + 58180334436 = 120259^2 + 241206^2 .

It is a cyclic number.

It is not a de Polignac number, because 72642561517 - 2¹¹ = 72642559469 is a prime.

It is a super-2 number, since 2×72642561517² (a number of 23 digits) 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 (72642561527) 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, 1813392 + ... + 1853017.

It is an arithmetic number, because the mean of its divisors is an integer number (18161561935).

Almost surely, 2^72642561517 is an apocalyptic number.

It is an amenable number.

72642561517 is a deficient number, since it is larger than the sum of its proper divisors (3686223).

72642561517 is a wasteful number, since it uses less digits than its factorization.

72642561517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3686222.

The product of its digits is 705600, while the sum is 46.

The spelling of 72642561517 in words is "seventy-two billion, six hundred forty-two million, five hundred sixty-one thousand, five hundred seventeen".