2157867689 has 2 divisors, whose sum is σ = 2157867690. Its totient is φ = 2157867688.

The previous prime is 2157867653. The next prime is 2157867703. The reversal of 2157867689 is 9867687512.

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., 2153424025 + 4443664 = 46405^2 + 2108^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2157867689 is a prime.

It is not a weakly prime, because it can be changed into another prime (2157867589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078933844 + 1078933845.

It is an arithmetic number, because the mean of its divisors is an integer number (1078933845).

Almost surely, 2^2157867689 is an apocalyptic number.

It is an amenable number.

2157867689 is a deficient number, since it is larger than the sum of its proper divisors (1).

2157867689 is an equidigital number, since it uses as much as digits as its factorization.

2157867689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10160640, while the sum is 59.

The square root of 2157867689 is about 46452.8544763398. The cubic root of 2157867689 is about 1292.2353105658.

The spelling of 2157867689 in words is "two billion, one hundred fifty-seven million, eight hundred sixty-seven thousand, six hundred eighty-nine".