19613903261 has 2 divisors, whose sum is σ = 19613903262. Its totient is φ = 19613903260.

The previous prime is 19613903213. The next prime is 19613903273. The reversal of 19613903261 is 16230931691.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18062016025 + 1551887236 = 134395^2 + 39394^2 .

It is a cyclic number.

It is not a de Polignac number, because 19613903261 - 2²² = 19609708957 is a prime.

It is a super-2 number, since 2×19613903261² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19613903201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9806951630 + 9806951631.

It is an arithmetic number, because the mean of its divisors is an integer number (9806951631).

Almost surely, 2^19613903261 is an apocalyptic number.

It is an amenable number.

19613903261 is a deficient number, since it is larger than the sum of its proper divisors (1).

19613903261 is an equidigital number, since it uses as much as digits as its factorization.

19613903261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 52488, while the sum is 41.

The spelling of 19613903261 in words is "nineteen billion, six hundred thirteen million, nine hundred three thousand, two hundred sixty-one".