51613635649 has 2 divisors, whose sum is σ = 51613635650. Its totient is φ = 51613635648.

The previous prime is 51613635643. The next prime is 51613635673. The reversal of 51613635649 is 94653631615.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 29607396624 + 22006239025 = 172068^2 + 148345^2 .

It is a cyclic number.

It is not a de Polignac number, because 51613635649 - 2²³ = 51605247041 is a prime.

It is not a weakly prime, because it can be changed into another prime (51613635643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25806817824 + 25806817825.

It is an arithmetic number, because the mean of its divisors is an integer number (25806817825).

Almost surely, 2^51613635649 is an apocalyptic number.

It is an amenable number.

51613635649 is a deficient number, since it is larger than the sum of its proper divisors (1).

51613635649 is an equidigital number, since it uses as much as digits as its factorization.

51613635649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1749600, while the sum is 49.

The spelling of 51613635649 in words is "fifty-one billion, six hundred thirteen million, six hundred thirty-five thousand, six hundred forty-nine".