2155321 has 4 divisors (see below), whose sum is σ = 2463232. Its totient is φ = 1847412.

The previous prime is 2155319. The next prime is 2155327. The reversal of 2155321 is 1235512.

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 not a de Polignac number, because 2155321 - 2¹ = 2155319 is a prime.

It is a super-2 number, since 2×2155321² = 9290817226082, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2155327) 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, 153945 + ... + 153958.

It is an arithmetic number, because the mean of its divisors is an integer number (615808).

2^2155321 is an apocalyptic number.

It is an amenable number.

2155321 is a deficient number, since it is larger than the sum of its proper divisors (307911).

2155321 is an equidigital number, since it uses as much as digits as its factorization.

2155321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 307910.

The product of its digits is 300, while the sum is 19.

The square root of 2155321 is about 1468.1011545531. The cubic root of 2155321 is about 129.1726750356.

The spelling of 2155321 in words is "two million, one hundred fifty-five thousand, three hundred twenty-one".