2156004 has 24 divisors (see below), whose sum is σ = 5589920. Its totient is φ = 718632.

The previous prime is 2155999. The next prime is 2156009. The reversal of 2156004 is 4006512.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (2155999) and next prime (2156009).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (2156009) 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, 9874 + ... + 10089.

2^2156004 is an apocalyptic number.

It is an amenable number.

2156004 is an abundant number, since it is smaller than the sum of its proper divisors (3433916).

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

2156004 is a wasteful number, since it uses less digits than its factorization.

2156004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19976 (or 19968 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 2156004 is about 1468.3337495270. Note that the first 3 decimals coincide. The cubic root of 2156004 is about 129.1863181108.

The spelling of 2156004 in words is "two million, one hundred fifty-six thousand, four".