2157911 has 12 divisors (see below), whose sum is σ = 2566368. Its totient is φ = 1808352.

The previous prime is 2157907. The next prime is 2157913. The reversal of 2157911 is 1197512.

It is not a de Polignac number, because 2157911 - 2² = 2157907 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2157913) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1835 + ... + 2771.

It is an arithmetic number, because the mean of its divisors is an integer number (213864).

2^2157911 is an apocalyptic number.

2157911 is a deficient number, since it is larger than the sum of its proper divisors (408457).

2157911 is an equidigital number, since it uses as much as digits as its factorization.

2157911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 998 (or 991 counting only the distinct ones).

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

The square root of 2157911 is about 1468.9829815216. The cubic root of 2157911 is about 129.2243956080.

The spelling of 2157911 in words is "two million, one hundred fifty-seven thousand, nine hundred eleven".