51420431 has 4 divisors (see below), whose sum is σ = 51555072. Its totient is φ = 51285792.

The previous prime is 51420419. The next prime is 51420443. The reversal of 51420431 is 13402415.

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

It is an interprime number because it is at equal distance from previous prime (51420419) and next prime (51420443).

It is a cyclic number.

It is not a de Polignac number, because 51420431 - 2⁶ = 51420367 is a prime.

It is a super-2 number, since 2×51420431² = 5288121448451522, 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 (51420331) 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, 66746 + ... + 67511.

It is an arithmetic number, because the mean of its divisors is an integer number (12888768).

Almost surely, 2^51420431 is an apocalyptic number.

51420431 is a deficient number, since it is larger than the sum of its proper divisors (134641).

51420431 is a wasteful number, since it uses less digits than its factorization.

51420431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134640.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 51420431 is about 7170.8040692798. The cubic root of 51420431 is about 371.8592344233.

Adding to 51420431 its reverse (13402415), we get a palindrome (64822846).

The spelling of 51420431 in words is "fifty-one million, four hundred twenty thousand, four hundred thirty-one".