19919087 has 16 divisors (see below), whose sum is σ = 22498560. Its totient is φ = 17523072.

The previous prime is 19919083. The next prime is 19919093. The reversal of 19919087 is 78091991.

It is a cyclic number.

It is not a de Polignac number, because 19919087 - 2² = 19919083 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19919083) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26438 + ... + 27180.

It is an arithmetic number, because the mean of its divisors is an integer number (1406160).

Almost surely, 2^19919087 is an apocalyptic number.

19919087 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

19919087 is a deficient number, since it is larger than the sum of its proper divisors (2579473).

19919087 is a wasteful number, since it uses less digits than its factorization.

19919087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 862.

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

The square root of 19919087 is about 4463.0804384416. The cubic root of 19919087 is about 271.0752141188.

The spelling of 19919087 in words is "nineteen million, nine hundred nineteen thousand, eighty-seven".