2101961565 has 24 divisors (see below), whose sum is σ = 3974619168. Its totient is φ = 1019132640.

The previous prime is 2101961551. The next prime is 2101961567. The reversal of 2101961565 is 5651691012.

2101961565 is a `hidden beast` number, since 2 + 1 + 0 + 1 + 96 + 1 + 565 = 666.

It is not a de Polignac number, because 2101961565 - 2⁷ = 2101961437 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2101961567) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2122699 + ... + 2123688.

It is an arithmetic number, because the mean of its divisors is an integer number (165609132).

Almost surely, 2^2101961565 is an apocalyptic number.

It is an amenable number.

2101961565 is a deficient number, since it is larger than the sum of its proper divisors (1872657603).

2101961565 is a wasteful number, since it uses less digits than its factorization.

2101961565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4246409 (or 4246406 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 36.

The square root of 2101961565 is about 45847.1543827968. The cubic root of 2101961565 is about 1280.9777614255.

The spelling of 2101961565 in words is "two billion, one hundred one million, nine hundred sixty-one thousand, five hundred sixty-five".