2151917 has 2 divisors, whose sum is σ = 2151918. Its totient is φ = 2151916.

The previous prime is 2151899. The next prime is 2151923. The reversal of 2151917 is 7191512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1674436 + 477481 = 1294^2 + 691^2 .

It is a cyclic number.

It is not a de Polignac number, because 2151917 - 2¹⁴ = 2135533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2151977) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1075958 + 1075959.

It is an arithmetic number, because the mean of its divisors is an integer number (1075959).

2^2151917 is an apocalyptic number.

It is an amenable number.

2151917 is a deficient number, since it is larger than the sum of its proper divisors (1).

2151917 is an equidigital number, since it uses as much as digits as its factorization.

2151917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 630, while the sum is 26.

The square root of 2151917 is about 1466.9413757884. The cubic root of 2151917 is about 129.1046363736.

The spelling of 2151917 in words is "two million, one hundred fifty-one thousand, nine hundred seventeen".