2156793209 has 2 divisors, whose sum is σ = 2156793210. Its totient is φ = 2156793208.

The previous prime is 2156793193. The next prime is 2156793211. The reversal of 2156793209 is 9023976512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2122629184 + 34164025 = 46072^2 + 5845^2 .

It is a cyclic number.

It is not a de Polignac number, because 2156793209 - 2⁴ = 2156793193 is a prime.

It is a super-3 number, since 3×2156793209³ (a number of 29 digits) contains 333 as substring.

Together with 2156793211, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2156793209.

It is not a weakly prime, because it can be changed into another prime (2156793229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078396604 + 1078396605.

It is an arithmetic number, because the mean of its divisors is an integer number (1078396605).

Almost surely, 2^2156793209 is an apocalyptic number.

It is an amenable number.

2156793209 is a deficient number, since it is larger than the sum of its proper divisors (1).

2156793209 is an equidigital number, since it uses as much as digits as its factorization.

2156793209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 204120, while the sum is 44.

The square root of 2156793209 is about 46441.2877620765. The cubic root of 2156793209 is about 1292.0207914635.

The spelling of 2156793209 in words is "two billion, one hundred fifty-six million, seven hundred ninety-three thousand, two hundred nine".