19961289149 has 2 divisors, whose sum is σ = 19961289150. Its totient is φ = 19961289148.

The previous prime is 19961289121. The next prime is 19961289203. The reversal of 19961289149 is 94198216991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15548344249 + 4412944900 = 124693^2 + 66430^2 .

It is a cyclic number.

It is not a de Polignac number, because 19961289149 - 2¹⁶ = 19961223613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19961280149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9980644574 + 9980644575.

It is an arithmetic number, because the mean of its divisors is an integer number (9980644575).

Almost surely, 2^19961289149 is an apocalyptic number.

It is an amenable number.

19961289149 is a deficient number, since it is larger than the sum of its proper divisors (1).

19961289149 is an equidigital number, since it uses as much as digits as its factorization.

19961289149 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2519424, while the sum is 59.

The spelling of 19961289149 in words is "nineteen billion, nine hundred sixty-one million, two hundred eighty-nine thousand, one hundred forty-nine".