7215321 has 4 divisors (see below), whose sum is σ = 9620432. Its totient is φ = 4810212.

The previous prime is 7215301. The next prime is 7215323. The reversal of 7215321 is 1235127.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1235127 = 3 ⋅411709.

It is not a de Polignac number, because 7215321 - 2¹¹ = 7213273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7215323) 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, 1202551 + ... + 1202556.

It is an arithmetic number, because the mean of its divisors is an integer number (2405108).

Almost surely, 2^7215321 is an apocalyptic number.

It is an amenable number.

7215321 is a deficient number, since it is larger than the sum of its proper divisors (2405111).

7215321 is a wasteful number, since it uses less digits than its factorization.

7215321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2405110.

The product of its digits is 420, while the sum is 21.

The square root of 7215321 is about 2686.1349556565. The cubic root of 7215321 is about 193.2347452824.

The spelling of 7215321 in words is "seven million, two hundred fifteen thousand, three hundred twenty-one".