2157109 has 2 divisors, whose sum is σ = 2157110. Its totient is φ = 2157108.

The previous prime is 2157097. The next prime is 2157119. The reversal of 2157109 is 9017512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1096209 + 1060900 = 1047^2 + 1030^2 .

It is a cyclic number.

It is not a de Polignac number, because 2157109 - 2⁹ = 2156597 is a prime.

It is an Ulam number.

2157109 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2157119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078554 + 1078555.

It is an arithmetic number, because the mean of its divisors is an integer number (1078555).

2^2157109 is an apocalyptic number.

It is an amenable number.

2157109 is a deficient number, since it is larger than the sum of its proper divisors (1).

2157109 is an equidigital number, since it uses as much as digits as its factorization.

2157109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 630, while the sum is 25.

The square root of 2157109 is about 1468.7099781781. The cubic root of 2157109 is about 129.2083846284.

The spelling of 2157109 in words is "two million, one hundred fifty-seven thousand, one hundred nine".