2161201923 has 24 divisors (see below), whose sum is σ = 3263589888. Its totient is φ = 1375566192.

The previous prime is 2161201901. The next prime is 2161201937. The reversal of 2161201923 is 3291021612.

2161201923 is a `hidden beast` number, since 21 + 612 + 0 + 1 + 9 + 23 = 666.

It is not a de Polignac number, because 2161201923 - 2⁸ = 2161201667 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2161001923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 103686 + ... + 122772.

It is an arithmetic number, because the mean of its divisors is an integer number (135982912).

Almost surely, 2^2161201923 is an apocalyptic number.

2161201923 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

2161201923 is a deficient number, since it is larger than the sum of its proper divisors (1102387965).

2161201923 is a wasteful number, since it uses less digits than its factorization.

2161201923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19663 (or 19660 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 2161201923 is about 46488.7289888635. The cubic root of 2161201923 is about 1292.9005348020.

The spelling of 2161201923 in words is "two billion, one hundred sixty-one million, two hundred one thousand, nine hundred twenty-three".