51403909 has 2 divisors, whose sum is σ = 51403910. Its totient is φ = 51403908.

The previous prime is 51403897. The next prime is 51403931. The reversal of 51403909 is 90930415.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50836900 + 567009 = 7130^2 + 753^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51403909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51403309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25701954 + 25701955.

It is an arithmetic number, because the mean of its divisors is an integer number (25701955).

Almost surely, 2^51403909 is an apocalyptic number.

It is an amenable number.

51403909 is a deficient number, since it is larger than the sum of its proper divisors (1).

51403909 is an equidigital number, since it uses as much as digits as its factorization.

51403909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4860, while the sum is 31.

The square root of 51403909 is about 7169.6519441323. The cubic root of 51403909 is about 371.8194025491.

The spelling of 51403909 in words is "fifty-one million, four hundred three thousand, nine hundred nine".