2157687 has 24 divisors (see below), whose sum is σ = 3687840. Its totient is φ = 1189440.

The previous prime is 2157679. The next prime is 2157709. The reversal of 2157687 is 7867512.

2157687 is a `hidden beast` number, since 2 + 1 + 576 + 87 = 666.

It is not a de Polignac number, because 2157687 - 2³ = 2157679 is a prime.

It is a super-2 number, since 2×2157687² = 9311226379938, which contains 22 as substring.

2157687 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2157667) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1237 + ... + 2417.

It is an arithmetic number, because the mean of its divisors is an integer number (153660).

2^2157687 is an apocalyptic number.

2157687 is a deficient number, since it is larger than the sum of its proper divisors (1530153).

2157687 is a wasteful number, since it uses less digits than its factorization.

2157687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1223 (or 1220 counting only the distinct ones).

The product of its digits is 23520, while the sum is 36.

The square root of 2157687 is about 1468.9067363179. The cubic root of 2157687 is about 129.2199241128.

The spelling of 2157687 in words is "two million, one hundred fifty-seven thousand, six hundred eighty-seven".