2656215221 has 16 divisors (see below), whose sum is σ = 2967664128. Its totient is φ = 2356527600.

The previous prime is 2656215203. The next prime is 2656215229. The reversal of 2656215221 is 1225126562.

It is a cyclic number.

It is not a de Polignac number, because 2656215221 - 2¹⁸ = 2655953077 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2656215229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 864530 + ... + 867596.

It is an arithmetic number, because the mean of its divisors is an integer number (185479008).

Almost surely, 2^2656215221 is an apocalyptic number.

It is an amenable number.

2656215221 is a deficient number, since it is larger than the sum of its proper divisors (311448907).

2656215221 is a wasteful number, since it uses less digits than its factorization.

2656215221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4952.

The product of its digits is 14400, while the sum is 32.

The square root of 2656215221 is about 51538.4829132562. The cubic root of 2656215221 is about 1384.9085198085.

The spelling of 2656215221 in words is "two billion, six hundred fifty-six million, two hundred fifteen thousand, two hundred twenty-one".