5131221 has 4 divisors (see below), whose sum is σ = 6841632. Its totient is φ = 3420812.

The previous prime is 5131219. The next prime is 5131223. The reversal of 5131221 is 1221315.

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 an interprime number because it is at equal distance from previous prime (5131219) and next prime (5131223).

It is a cyclic number.

It is not a de Polignac number, because 5131221 - 2¹ = 5131219 is a prime.

It is a D-number.

It is a self number, because there is not a number n which added to its sum of digits gives 5131221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5131223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 855201 + ... + 855206.

It is an arithmetic number, because the mean of its divisors is an integer number (1710408).

Almost surely, 2^5131221 is an apocalyptic number.

It is an amenable number.

5131221 is a deficient number, since it is larger than the sum of its proper divisors (1710411).

5131221 is a wasteful number, since it uses less digits than its factorization.

5131221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1710410.

The product of its digits is 60, while the sum is 15.

The square root of 5131221 is about 2265.2198568792. The cubic root of 5131221 is about 172.4805943303.

Subtracting from 5131221 its sum of digits (15), we obtain a triangular number (5131206 = T₃₂₀₃).

Adding to 5131221 its reverse (1221315), we get a palindrome (6352536).

The spelling of 5131221 in words is "five million, one hundred thirty-one thousand, two hundred twenty-one".