2156664 has 32 divisors (see below), whose sum is σ = 5627520. Its totient is φ = 687456.

The previous prime is 2156659. The next prime is 2156669. The reversal of 2156664 is 4666512.

It is an interprime number because it is at equal distance from previous prime (2156659) and next prime (2156669).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2156669) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1402 + ... + 2505.

It is an arithmetic number, because the mean of its divisors is an integer number (175860).

2^2156664 is an apocalyptic number.

2156664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

2156664 is an abundant number, since it is smaller than the sum of its proper divisors (3470856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2156664 is a wasteful number, since it uses less digits than its factorization.

2156664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3939 (or 3935 counting only the distinct ones).

The product of its digits is 8640, while the sum is 30.

The square root of 2156664 is about 1468.5584768745. The cubic root of 2156664 is about 129.1994990188.

The spelling of 2156664 in words is "two million, one hundred fifty-six thousand, six hundred sixty-four".