51551551662409 has 2 divisors, whose sum is σ = 51551551662410. Its totient is φ = 51551551662408.

The previous prime is 51551551662323. The next prime is 51551551662427. The reversal of 51551551662409 is 90426615515515.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35388257132809 + 16163294529600 = 5948803^2 + 4020360^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51551551662409 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51551551662409.

It is not a weakly prime, because it can be changed into another prime (51551551672409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25775775831204 + 25775775831205.

It is an arithmetic number, because the mean of its divisors is an integer number (25775775831205).

Almost surely, 2^{51551551662409} is an apocalyptic number.

It is an amenable number.

51551551662409 is a deficient number, since it is larger than the sum of its proper divisors (1).

51551551662409 is an equidigital number, since it uses as much as digits as its factorization.

51551551662409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8100000, while the sum is 55.

The spelling of 51551551662409 in words is "fifty-one trillion, five hundred fifty-one billion, five hundred fifty-one million, six hundred sixty-two thousand, four hundred nine".