2157945161 has 2 divisors, whose sum is σ = 2157945162. Its totient is φ = 2157945160.

The previous prime is 2157945107. The next prime is 2157945193. The reversal of 2157945161 is 1615497512.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1880089600 + 277855561 = 43360^2 + 16669^2 .

It is a cyclic number.

It is not a de Polignac number, because 2157945161 - 2²² = 2153750857 is a prime.

It is not a weakly prime, because it can be changed into another prime (2157935161) 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, 1078972580 + 1078972581.

It is an arithmetic number, because the mean of its divisors is an integer number (1078972581).

Almost surely, 2^2157945161 is an apocalyptic number.

It is an amenable number.

2157945161 is a deficient number, since it is larger than the sum of its proper divisors (1).

2157945161 is an equidigital number, since it uses as much as digits as its factorization.

2157945161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 75600, while the sum is 41.

The square root of 2157945161 is about 46453.6883465673. The cubic root of 2157945161 is about 1292.2507750382.

The spelling of 2157945161 in words is "two billion, one hundred fifty-seven million, nine hundred forty-five thousand, one hundred sixty-one".