2161515604 has 12 divisors (see below), whose sum is σ = 3792796084. Its totient is φ = 1077859584.

The previous prime is 2161515599. The next prime is 2161515607. The reversal of 2161515604 is 4065151612.

It can be written as a sum of positive squares in 2 ways, for example, as 852523204 + 1308992400 = 29198^2 + 36180^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161515607) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 722877 + ... + 725860.

Almost surely, 2^2161515604 is an apocalyptic number.

It is an amenable number.

2161515604 is a deficient number, since it is larger than the sum of its proper divisors (1631280480).

2161515604 is a wasteful number, since it uses less digits than its factorization.

2161515604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1449114 (or 1449112 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 31.

The square root of 2161515604 is about 46492.1025981833. The cubic root of 2161515604 is about 1292.9630831320.

The spelling of 2161515604 in words is "two billion, one hundred sixty-one million, five hundred fifteen thousand, six hundred four".