72782638517 has 2 divisors, whose sum is σ = 72782638518. Its totient is φ = 72782638516.

The previous prime is 72782638499. The next prime is 72782638571. The reversal of 72782638517 is 71583628727.

Together with next prime (72782638571) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50876862481 + 21905776036 = 225559^2 + 148006^2 .

It is a cyclic number.

It is not a de Polignac number, because 72782638517 - 2⁸ = 72782638261 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72782638217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36391319258 + 36391319259.

It is an arithmetic number, because the mean of its divisors is an integer number (36391319259).

Almost surely, 2^72782638517 is an apocalyptic number.

It is an amenable number.

72782638517 is a deficient number, since it is larger than the sum of its proper divisors (1).

72782638517 is an equidigital number, since it uses as much as digits as its factorization.

72782638517 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7902720, while the sum is 56.

The spelling of 72782638517 in words is "seventy-two billion, seven hundred eighty-two million, six hundred thirty-eight thousand, five hundred seventeen".