2109890957 has 2 divisors, whose sum is σ = 2109890958. Its totient is φ = 2109890956.

The previous prime is 2109890953. The next prime is 2109891001. The reversal of 2109890957 is 7590989012.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1315440361 + 794450596 = 36269^2 + 28186^2 .

It is a cyclic number.

It is not a de Polignac number, because 2109890957 - 2² = 2109890953 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2109890953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1054945478 + 1054945479.

It is an arithmetic number, because the mean of its divisors is an integer number (1054945479).

Almost surely, 2^2109890957 is an apocalyptic number.

It is an amenable number.

2109890957 is a deficient number, since it is larger than the sum of its proper divisors (1).

2109890957 is an equidigital number, since it uses as much as digits as its factorization.

2109890957 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 408240, while the sum is 50.

The square root of 2109890957 is about 45933.5493620948. The cubic root of 2109890957 is about 1282.5865172975.

The spelling of 2109890957 in words is "two billion, one hundred nine million, eight hundred ninety thousand, nine hundred fifty-seven".