19661947967 has 2 divisors, whose sum is σ = 19661947968. Its totient is φ = 19661947966.

The previous prime is 19661947913. The next prime is 19661947999. The reversal of 19661947967 is 76974916691.

It is a strong prime.

It is an emirp because it is prime and its reverse (76974916691) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19661947967 - 2¹⁶ = 19661882431 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19661947267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9830973983 + 9830973984.

It is an arithmetic number, because the mean of its divisors is an integer number (9830973984).

Almost surely, 2^19661947967 is an apocalyptic number.

19661947967 is a deficient number, since it is larger than the sum of its proper divisors (1).

19661947967 is an equidigital number, since it uses as much as digits as its factorization.

19661947967 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30862944, while the sum is 65.

The spelling of 19661947967 in words is "nineteen billion, six hundred sixty-one million, nine hundred forty-seven thousand, nine hundred sixty-seven".