2107665221 has 6 divisors (see below), whose sum is σ = 2113470450. Its totient is φ = 2101875888.

The previous prime is 2107665211. The next prime is 2107665233. The reversal of 2107665221 is 1225667012.

It can be written as a sum of positive squares in 3 ways, for example, as 558376900 + 1549288321 = 23630^2 + 39361^2 .

It is a de Polignac number, because none of the positive numbers 2^k-2107665221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2107665211) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 131555 + ... + 146703.

It is an arithmetic number, because the mean of its divisors is an integer number (352245075).

Almost surely, 2^2107665221 is an apocalyptic number.

It is an amenable number.

2107665221 is a deficient number, since it is larger than the sum of its proper divisors (5805229).

2107665221 is an frugal number, since it uses more digits than its factorization.

2107665221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15895 (or 15522 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 2107665221 is about 45909.3151876610. The cubic root of 2107665221 is about 1282.1353560062.

The spelling of 2107665221 in words is "two billion, one hundred seven million, six hundred sixty-five thousand, two hundred twenty-one".