51090509 has 2 divisors, whose sum is σ = 51090510. Its totient is φ = 51090508.

The previous prime is 51090503. The next prime is 51090517. The reversal of 51090509 is 90509015.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 33028009 + 18062500 = 5747^2 + 4250^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51090509 is a prime.

It is a super-2 number, since 2×51090509² = 5220480219758162, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51090503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25545254 + 25545255.

It is an arithmetic number, because the mean of its divisors is an integer number (25545255).

Almost surely, 2^51090509 is an apocalyptic number.

It is an amenable number.

51090509 is a deficient number, since it is larger than the sum of its proper divisors (1).

51090509 is an equidigital number, since it uses as much as digits as its factorization.

51090509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2025, while the sum is 29.

The square root of 51090509 is about 7147.7625170399. The cubic root of 51090509 is about 371.0622239266.

It can be divided in two parts, 510 and 90509, that added together give a palindrome (91019).

The spelling of 51090509 in words is "fifty-one million, ninety thousand, five hundred nine".