2154021 has 4 divisors (see below), whose sum is σ = 2872032. Its totient is φ = 1436012.

The previous prime is 2154013. The next prime is 2154037. The reversal of 2154021 is 1204512.

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 2154021 - 2³ = 2154013 is a prime.

It is a D-number.

It is a Curzon number.

2154021 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2154041) 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, 359001 + ... + 359006.

It is an arithmetic number, because the mean of its divisors is an integer number (718008).

2^2154021 is an apocalyptic number.

It is an amenable number.

2154021 is a deficient number, since it is larger than the sum of its proper divisors (718011).

2154021 is an equidigital number, since it uses as much as digits as its factorization.

2154021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 718010.

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 2154021 is about 1467.6583389877. The cubic root of 2154021 is about 129.1466992837.

Adding to 2154021 its reverse (1204512), we get a palindrome (3358533).

The spelling of 2154021 in words is "two million, one hundred fifty-four thousand, twenty-one".