2120921 has 4 divisors (see below), whose sum is σ = 2313744. Its totient is φ = 1928100.

The previous prime is 2120917. The next prime is 2120933. The reversal of 2120921 is 1290212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2120921 - 2² = 2120917 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 2120921.

It is not an unprimeable number, because it can be changed into a prime (2120941) 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, 96395 + ... + 96416.

It is an arithmetic number, because the mean of its divisors is an integer number (578436).

2^2120921 is an apocalyptic number.

It is an amenable number.

2120921 is a deficient number, since it is larger than the sum of its proper divisors (192823).

2120921 is a wasteful number, since it uses less digits than its factorization.

2120921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192822.

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 2120921 is about 1456.3382162122. The cubic root of 2120921 is about 128.4817659987.

The spelling of 2120921 in words is "two million, one hundred twenty thousand, nine hundred twenty-one".