51406309 has 2 divisors, whose sum is σ = 51406310. Its totient is φ = 51406308.

The previous prime is 51406307. The next prime is 51406319. The reversal of 51406309 is 90360415.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49773025 + 1633284 = 7055^2 + 1278^2 .

It is a cyclic number.

It is not a de Polignac number, because 51406309 - 2¹ = 51406307 is a prime.

Together with 51406307, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51406301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25703154 + 25703155.

It is an arithmetic number, because the mean of its divisors is an integer number (25703155).

Almost surely, 2^51406309 is an apocalyptic number.

It is an amenable number.

51406309 is a deficient number, since it is larger than the sum of its proper divisors (1).

51406309 is an equidigital number, since it uses as much as digits as its factorization.

51406309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 51406309 is about 7169.8193143203. The cubic root of 51406309 is about 371.8251890914.

It can be divided in two parts, 51406 and 309, that added together give a palindrome (51715).

The spelling of 51406309 in words is "fifty-one million, four hundred six thousand, three hundred nine".