2156245181 has 2 divisors, whose sum is σ = 2156245182. Its totient is φ = 2156245180.

The previous prime is 2156245139. The next prime is 2156245187. The reversal of 2156245181 is 1815426512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1307979556 + 848265625 = 36166^2 + 29125^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2156245181 is a prime.

It is a super-2 number, since 2×2156245181² = 9298786561171445522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2156245187) 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, 1078122590 + 1078122591.

It is an arithmetic number, because the mean of its divisors is an integer number (1078122591).

Almost surely, 2^2156245181 is an apocalyptic number.

It is an amenable number.

2156245181 is a deficient number, since it is larger than the sum of its proper divisors (1).

2156245181 is an equidigital number, since it uses as much as digits as its factorization.

2156245181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19200, while the sum is 35.

The square root of 2156245181 is about 46435.3871632401. The cubic root of 2156245181 is about 1291.9113506592.

The spelling of 2156245181 in words is "two billion, one hundred fifty-six million, two hundred forty-five thousand, one hundred eighty-one".