51115409 has 2 divisors, whose sum is σ = 51115410. Its totient is φ = 51115408.

The previous prime is 51115399. The next prime is 51115423. The reversal of 51115409 is 90451115.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 43191184 + 7924225 = 6572^2 + 2815^2 .

It is a cyclic number.

It is not a de Polignac number, because 51115409 - 2⁸ = 51115153 is a prime.

It is a super-2 number, since 2×51115409² = 5225570074474562, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (51115469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25557704 + 25557705.

It is an arithmetic number, because the mean of its divisors is an integer number (25557705).

Almost surely, 2^51115409 is an apocalyptic number.

It is an amenable number.

51115409 is a deficient number, since it is larger than the sum of its proper divisors (1).

51115409 is an equidigital number, since it uses as much as digits as its factorization.

51115409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 900, while the sum is 26.

The square root of 51115409 is about 7149.5041086777. The cubic root of 51115409 is about 371.1224957132.

The spelling of 51115409 in words is "fifty-one million, one hundred fifteen thousand, four hundred nine".