5101661561 has 2 divisors, whose sum is σ = 5101661562. Its totient is φ = 5101661560.

The previous prime is 5101661507. The next prime is 5101661567. The reversal of 5101661561 is 1651661015.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4723125625 + 378535936 = 68725^2 + 19456^2 .

It is a cyclic number.

It is not a de Polignac number, because 5101661561 - 2⁶ = 5101661497 is a prime.

It is not a weakly prime, because it can be changed into another prime (5101661567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2550830780 + 2550830781.

It is an arithmetic number, because the mean of its divisors is an integer number (2550830781).

Almost surely, 2^5101661561 is an apocalyptic number.

It is an amenable number.

5101661561 is a deficient number, since it is larger than the sum of its proper divisors (1).

5101661561 is an equidigital number, since it uses as much as digits as its factorization.

5101661561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5400, while the sum is 32.

The square root of 5101661561 is about 71425.9165919486. The cubic root of 5101661561 is about 1721.4875315394.

The spelling of 5101661561 in words is "five billion, one hundred one million, six hundred sixty-one thousand, five hundred sixty-one".