13222731 has 4 divisors (see below), whose sum is σ = 17630312. Its totient is φ = 8815152.

The previous prime is 13222717. The next prime is 13222733. The reversal of 13222731 is 13722231.

13222731 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13722231 = 3 ⋅4574077.

It is not a de Polignac number, because 13222731 - 2⁷ = 13222603 is a prime.

It is a super-2 number, since 2×13222731² = 349681230196722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13222698 and 13222707.

It is not an unprimeable number, because it can be changed into a prime (13222733) 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, 2203786 + ... + 2203791.

It is an arithmetic number, because the mean of its divisors is an integer number (4407578).

Almost surely, 2^13222731 is an apocalyptic number.

13222731 is a deficient number, since it is larger than the sum of its proper divisors (4407581).

13222731 is an equidigital number, since it uses as much as digits as its factorization.

13222731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4407580.

The product of its digits is 504, while the sum is 21.

The square root of 13222731 is about 3636.3073302459. The cubic root of 13222731 is about 236.4687311067.

Adding to 13222731 its reverse (13722231), we get a palindrome (26944962).

Subtracting 13222731 from its reverse (13722231), we obtain a triangular number (499500 = T₉₉₉).

The spelling of 13222731 in words is "thirteen million, two hundred twenty-two thousand, seven hundred thirty-one".