8216568261 has 32 divisors (see below), whose sum is σ = 13410829440. Its totient is φ = 4930416000.

The previous prime is 8216568257. The next prime is 8216568263. The reversal of 8216568261 is 1628656128.

8216568261 is a `hidden beast` number, since 8 + 21 + 6 + 568 + 2 + 61 = 666.

It is not a de Polignac number, because 8216568261 - 2² = 8216568257 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8216568263) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 106960 + ... + 166953.

It is an arithmetic number, because the mean of its divisors is an integer number (419088420).

Almost surely, 2^8216568261 is an apocalyptic number.

It is an amenable number.

8216568261 is a deficient number, since it is larger than the sum of its proper divisors (5194261179).

8216568261 is a wasteful number, since it uses less digits than its factorization.

8216568261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 274034 (or 274028 counting only the distinct ones).

The product of its digits is 276480, while the sum is 45.

The square root of 8216568261 is about 90645.2881345743. The cubic root of 8216568261 is about 2017.8869074572.

It can be divided in two parts, 82165 and 68261, that added together give a triangular number (150426 = T₅₄₈).

The spelling of 8216568261 in words is "eight billion, two hundred sixteen million, five hundred sixty-eight thousand, two hundred sixty-one".