19807919 has 2 divisors, whose sum is σ = 19807920. Its totient is φ = 19807918.

The previous prime is 19807903. The next prime is 19807939. The reversal of 19807919 is 91970891.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19807919 - 2⁴ = 19807903 is a prime.

It is a super-2 number, since 2×19807919² = 784707310221122, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19807919.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19807939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9903959 + 9903960.

It is an arithmetic number, because the mean of its divisors is an integer number (9903960).

Almost surely, 2^19807919 is an apocalyptic number.

19807919 is a deficient number, since it is larger than the sum of its proper divisors (1).

19807919 is an equidigital number, since it uses as much as digits as its factorization.

19807919 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40824, while the sum is 44.

The square root of 19807919 is about 4450.6088347551. The cubic root of 19807919 is about 270.5699847276.

The spelling of 19807919 in words is "nineteen million, eight hundred seven thousand, nine hundred nineteen".