7513221 has 4 divisors (see below), whose sum is σ = 10017632. Its totient is φ = 5008812.

The previous prime is 7513213. The next prime is 7513223. The reversal of 7513221 is 1223157.

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 7513221 - 2³ = 7513213 is a prime.

It is a Duffinian number.

It is a Curzon number.

7513221 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7513223) 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, 1252201 + ... + 1252206.

It is an arithmetic number, because the mean of its divisors is an integer number (2504408).

Almost surely, 2^7513221 is an apocalyptic number.

It is an amenable number.

7513221 is a deficient number, since it is larger than the sum of its proper divisors (2504411).

7513221 is a wasteful number, since it uses less digits than its factorization.

7513221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2504410.

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

The square root of 7513221 is about 2741.0255380058. The cubic root of 7513221 is about 195.8583333508.

Adding to 7513221 its reverse (1223157), we get a palindrome (8736378).

Subtracting from 7513221 its reverse (1223157), we obtain a square (6290064 = 2508²).

The spelling of 7513221 in words is "seven million, five hundred thirteen thousand, two hundred twenty-one".