51432509 has 2 divisors, whose sum is σ = 51432510. Its totient is φ = 51432508.

The previous prime is 51432499. The next prime is 51432547. The reversal of 51432509 is 90523415.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44023225 + 7409284 = 6635^2 + 2722^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51432509 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51432559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25716254 + 25716255.

It is an arithmetic number, because the mean of its divisors is an integer number (25716255).

Almost surely, 2^51432509 is an apocalyptic number.

It is an amenable number.

51432509 is a deficient number, since it is larger than the sum of its proper divisors (1).

51432509 is an equidigital number, since it uses as much as digits as its factorization.

51432509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 51432509 is about 7171.6461848030. The cubic root of 51432509 is about 371.8883471329. Note that the first 3 decimals are identical.

The spelling of 51432509 in words is "fifty-one million, four hundred thirty-two thousand, five hundred nine".