51072431 has 4 divisors (see below), whose sum is σ = 51093864. Its totient is φ = 51051000.

The previous prime is 51072391. The next prime is 51072449. The reversal of 51072431 is 13427015.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51072431 is a prime.

It is a super-2 number, since 2×51072431² = 5216786416499522, 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 = 51072397 and 51072406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51072331) 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, 6620 + ... + 12081.

It is an arithmetic number, because the mean of its divisors is an integer number (12773466).

Almost surely, 2^51072431 is an apocalyptic number.

51072431 is a deficient number, since it is larger than the sum of its proper divisors (21433).

51072431 is a wasteful number, since it uses less digits than its factorization.

51072431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21432.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 51072431 is about 7146.4978136147. The cubic root of 51072431 is about 371.0184528859.

Adding to 51072431 its reverse (13427015), we get a palindrome (64499446).

The spelling of 51072431 in words is "fifty-one million, seventy-two thousand, four hundred thirty-one".