51357409 has 2 divisors, whose sum is σ = 51357410. Its totient is φ = 51357408.

The previous prime is 51357407. The next prime is 51357419. The reversal of 51357409 is 90475315.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 51265600 + 91809 = 7160^2 + 303^2 .

It is a cyclic number.

It is not a de Polignac number, because 51357409 - 2¹ = 51357407 is a prime.

Together with 51357407, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (51357401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25678704 + 25678705.

It is an arithmetic number, because the mean of its divisors is an integer number (25678705).

Almost surely, 2^51357409 is an apocalyptic number.

It is an amenable number.

51357409 is a deficient number, since it is larger than the sum of its proper divisors (1).

51357409 is an equidigital number, since it uses as much as digits as its factorization.

51357409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18900, while the sum is 34.

The square root of 51357409 is about 7166.4083751905. The cubic root of 51357409 is about 371.7072527238.

It can be divided in two parts, 5135 and 7409, that added together give a square (12544 = 112²).

The spelling of 51357409 in words is "fifty-one million, three hundred fifty-seven thousand, four hundred nine".