19963871 has 2 divisors, whose sum is σ = 19963872. Its totient is φ = 19963870.

The previous prime is 19963841. The next prime is 19963877. The reversal of 19963871 is 17836991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19963871 - 2⁶ = 19963807 is a prime.

It is a super-2 number, since 2×19963871² = 797112290609282, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19963877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9981935 + 9981936.

It is an arithmetic number, because the mean of its divisors is an integer number (9981936).

Almost surely, 2^19963871 is an apocalyptic number.

19963871 is a deficient number, since it is larger than the sum of its proper divisors (1).

19963871 is an equidigital number, since it uses as much as digits as its factorization.

19963871 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81648, while the sum is 44.

The square root of 19963871 is about 4468.0947841334. The cubic root of 19963871 is about 271.2782144832.

The spelling of 19963871 in words is "nineteen million, nine hundred sixty-three thousand, eight hundred seventy-one".