215672766517 has 18 divisors (see below), whose sum is σ = 234085757346. Its totient is φ = 197532280800.

The previous prime is 215672766499. The next prime is 215672766553. The reversal of 215672766517 is 715667276512.

It can be written as a sum of positive squares in 3 ways, for example, as 24709010481 + 190963756036 = 157191^2 + 436994^2 .

It is not a de Polignac number, because 215672766517 - 2¹¹ = 215672764469 is a prime.

It is a super-2 number, since 2×215672766517² (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 (215672766577) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 252839863 + ... + 252840715.

It is an arithmetic number, because the mean of its divisors is an integer number (13004764297).

Almost surely, 2^215672766517 is an apocalyptic number.

It is an amenable number.

215672766517 is a deficient number, since it is larger than the sum of its proper divisors (18412990829).

215672766517 is an frugal number, since it uses more digits than its factorization.

215672766517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2021 (or 1017 counting only the distinct ones).

The product of its digits is 7408800, while the sum is 55.

The spelling of 215672766517 in words is "two hundred fifteen billion, six hundred seventy-two million, seven hundred sixty-six thousand, five hundred seventeen".