2156866 has 8 divisors (see below), whose sum is σ = 3256380. Its totient is φ = 1071408.

The previous prime is 2156857. The next prime is 2156867. The reversal of 2156866 is 6686512.

It can be written as a sum of positive squares in 2 ways, for example, as 1766241 + 390625 = 1329^2 + 625^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (2156867) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3121 + ... + 3748.

2^2156866 is an apocalyptic number.

2156866 is a deficient number, since it is larger than the sum of its proper divisors (1099514).

2156866 is a wasteful number, since it uses less digits than its factorization.

2156866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7028.

The product of its digits is 17280, while the sum is 34.

The square root of 2156866 is about 1468.6272501898. The cubic root of 2156866 is about 129.2035326380.

The spelling of 2156866 in words is "two million, one hundred fifty-six thousand, eight hundred sixty-six".