51440431 has 4 divisors (see below), whose sum is σ = 58789072. Its totient is φ = 44091792.

The previous prime is 51440393. The next prime is 51440437. The reversal of 51440431 is 13404415.

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

It is a cyclic number.

It is not a de Polignac number, because 51440431 - 2⁷ = 51440303 is a prime.

It is a super-2 number, since 2×51440431² = 5292235882931522, 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 (51440437) 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, 3674310 + ... + 3674323.

It is an arithmetic number, because the mean of its divisors is an integer number (14697268).

Almost surely, 2^51440431 is an apocalyptic number.

51440431 is a deficient number, since it is larger than the sum of its proper divisors (7348641).

51440431 is an equidigital number, since it uses as much as digits as its factorization.

51440431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7348640.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 51440431 is about 7172.1984774545. The cubic root of 51440431 is about 371.9074397801.

Adding to 51440431 its reverse (13404415), we get a palindrome (64844846).

The spelling of 51440431 in words is "fifty-one million, four hundred forty thousand, four hundred thirty-one".