51321431 has 4 divisors (see below), whose sum is σ = 58653072. Its totient is φ = 43989792.

The previous prime is 51321421. The next prime is 51321449. The reversal of 51321431 is 13412315.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 51321431 - 2¹⁴ = 51305047 is a prime.

It is a super-2 number, since 2×51321431² = 5267778559775522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51321401) 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, 3665810 + ... + 3665823.

It is an arithmetic number, because the mean of its divisors is an integer number (14663268).

Almost surely, 2^51321431 is an apocalyptic number.

51321431 is a deficient number, since it is larger than the sum of its proper divisors (7331641).

51321431 is an equidigital number, since it uses as much as digits as its factorization.

51321431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7331640.

The product of its digits is 360, while the sum is 20.

The square root of 51321431 is about 7163.8977519225. The cubic root of 51321431 is about 371.6204336529.

Adding to 51321431 its reverse (13412315), we get a palindrome (64733746).

The spelling of 51321431 in words is "fifty-one million, three hundred twenty-one thousand, four hundred thirty-one".