51505661659 has 2 divisors, whose sum is σ = 51505661660. Its totient is φ = 51505661658.

The previous prime is 51505661629. The next prime is 51505661677. The reversal of 51505661659 is 95616650515.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 51505661659 - 2¹³ = 51505653467 is a prime.

It is not a weakly prime, because it can be changed into another prime (51505661629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25752830829 + 25752830830.

It is an arithmetic number, because the mean of its divisors is an integer number (25752830830).

Almost surely, 2^51505661659 is an apocalyptic number.

51505661659 is a deficient number, since it is larger than the sum of its proper divisors (1).

51505661659 is an equidigital number, since it uses as much as digits as its factorization.

51505661659 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1215000, while the sum is 49.

The spelling of 51505661659 in words is "fifty-one billion, five hundred five million, six hundred sixty-one thousand, six hundred fifty-nine".