51513109 has 2 divisors, whose sum is σ = 51513110. Its totient is φ = 51513108.

The previous prime is 51513101. The next prime is 51513149. The reversal of 51513109 is 90131515.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 35070084 + 16443025 = 5922^2 + 4055^2 .

It is a cyclic number.

It is not a de Polignac number, because 51513109 - 2³ = 51513101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51513101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25756554 + 25756555.

It is an arithmetic number, because the mean of its divisors is an integer number (25756555).

Almost surely, 2^51513109 is an apocalyptic number.

It is an amenable number.

51513109 is a deficient number, since it is larger than the sum of its proper divisors (1).

51513109 is an equidigital number, since it uses as much as digits as its factorization.

51513109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 675, while the sum is 25.

The square root of 51513109 is about 7177.2633363978. The cubic root of 51513109 is about 372.0825080987.

The spelling of 51513109 in words is "fifty-one million, five hundred thirteen thousand, one hundred nine".