19967544823 has 2 divisors, whose sum is σ = 19967544824. Its totient is φ = 19967544822.

The previous prime is 19967544811. The next prime is 19967544833. The reversal of 19967544823 is 32844576991.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19967544823 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19967544833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9983772411 + 9983772412.

It is an arithmetic number, because the mean of its divisors is an integer number (9983772412).

Almost surely, 2^19967544823 is an apocalyptic number.

19967544823 is a deficient number, since it is larger than the sum of its proper divisors (1).

19967544823 is an equidigital number, since it uses as much as digits as its factorization.

19967544823 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13063680, while the sum is 58.

The spelling of 19967544823 in words is "nineteen billion, nine hundred sixty-seven million, five hundred forty-four thousand, eight hundred twenty-three".