2130921 has 24 divisors (see below), whose sum is σ = 3425760. Its totient is φ = 1308528.

The previous prime is 2130917. The next prime is 2130929. The reversal of 2130921 is 1290312.

It is a happy number.

It is not a de Polignac number, because 2130921 - 2² = 2130917 is a prime.

It is a Curzon number.

2130921 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 2130894 and 2130903.

It is not an unprimeable number, because it can be changed into a prime (2130929) 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, 4330 + ... + 4796.

It is an arithmetic number, because the mean of its divisors is an integer number (142740).

2^2130921 is an apocalyptic number.

It is an amenable number.

2130921 is a deficient number, since it is larger than the sum of its proper divisors (1294839).

2130921 is a wasteful number, since it uses less digits than its factorization.

2130921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 502 (or 483 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

The square root of 2130921 is about 1459.7674472326. The cubic root of 2130921 is about 128.6833771001.

The spelling of 2130921 in words is "two million, one hundred thirty thousand, nine hundred twenty-one".