51430391 has 2 divisors, whose sum is σ = 51430392. Its totient is φ = 51430390.

The previous prime is 51430387. The next prime is 51430399. The reversal of 51430391 is 19303415.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51430391 - 2² = 51430387 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51430391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51430399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25715195 + 25715196.

It is an arithmetic number, because the mean of its divisors is an integer number (25715196).

Almost surely, 2^51430391 is an apocalyptic number.

51430391 is a deficient number, since it is larger than the sum of its proper divisors (1).

51430391 is an equidigital number, since it uses as much as digits as its factorization.

51430391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1620, while the sum is 26.

The square root of 51430391 is about 7171.4985184409. The cubic root of 51430391 is about 371.8832422531.

The spelling of 51430391 in words is "fifty-one million, four hundred thirty thousand, three hundred ninety-one".