2156204109 has 4 divisors (see below), whose sum is σ = 2874938816. Its totient is φ = 1437469404.

The previous prime is 2156204093. The next prime is 2156204111. The reversal of 2156204109 is 9014026512.

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 not a de Polignac number, because 2156204109 - 2⁴ = 2156204093 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 (2156204159) 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, 359367349 + ... + 359367354.

It is an arithmetic number, because the mean of its divisors is an integer number (718734704).

Almost surely, 2^2156204109 is an apocalyptic number.

It is an amenable number.

2156204109 is a deficient number, since it is larger than the sum of its proper divisors (718734707).

2156204109 is an equidigital number, since it uses as much as digits as its factorization.

2156204109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 718734706.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 2156204109 is about 46434.9449122102. The cubic root of 2156204109 is about 1291.9031478629.

The spelling of 2156204109 in words is "two billion, one hundred fifty-six million, two hundred four thousand, one hundred nine".