2161398653 has 4 divisors (see below), whose sum is σ = 2161556160. Its totient is φ = 2161241148.

The previous prime is 2161398641. The next prime is 2161398661. The reversal of 2161398653 is 3568931612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2161398653 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 (2161391653) 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, 55973 + ... + 86346.

It is an arithmetic number, because the mean of its divisors is an integer number (540389040).

Almost surely, 2^2161398653 is an apocalyptic number.

It is an amenable number.

2161398653 is a deficient number, since it is larger than the sum of its proper divisors (157507).

2161398653 is a wasteful number, since it uses less digits than its factorization.

2161398653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157506.

The product of its digits is 233280, while the sum is 44.

The square root of 2161398653 is about 46490.8448299232. The cubic root of 2161398653 is about 1292.9397636839.

The spelling of 2161398653 in words is "two billion, one hundred sixty-one million, three hundred ninety-eight thousand, six hundred fifty-three".