19913863 has 2 divisors, whose sum is σ = 19913864. Its totient is φ = 19913862.

The previous prime is 19913779. The next prime is 19913869. The reversal of 19913863 is 36831991.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19913863 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19913869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9956931 + 9956932.

It is an arithmetic number, because the mean of its divisors is an integer number (9956932).

Almost surely, 2^19913863 is an apocalyptic number.

19913863 is a deficient number, since it is larger than the sum of its proper divisors (1).

19913863 is an equidigital number, since it uses as much as digits as its factorization.

19913863 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34992, while the sum is 40.

The square root of 19913863 is about 4462.4951540590. The cubic root of 19913863 is about 271.0515145598.

The spelling of 19913863 in words is "nineteen million, nine hundred thirteen thousand, eight hundred sixty-three".