11521431 has 6 divisors (see below), whose sum is σ = 16642080. Its totient is φ = 7680948.

The previous prime is 11521421. The next prime is 11521453. The reversal of 11521431 is 13412511.

It is not a de Polignac number, because 11521431 - 2⁷ = 11521303 is a prime.

It is a super-2 number, since 2×11521431² = 265486744575522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11521421) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 640071 + ... + 640088.

It is an arithmetic number, because the mean of its divisors is an integer number (2773680).

Almost surely, 2^11521431 is an apocalyptic number.

11521431 is a deficient number, since it is larger than the sum of its proper divisors (5120649).

11521431 is a wasteful number, since it uses less digits than its factorization.

11521431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1280165 (or 1280162 counting only the distinct ones).

The product of its digits is 120, while the sum is 18.

The square root of 11521431 is about 3394.3233493585. The cubic root of 11521431 is about 225.8579980898.

Adding to 11521431 its reverse (13412511), we get a palindrome (24933942).

The spelling of 11521431 in words is "eleven million, five hundred twenty-one thousand, four hundred thirty-one".