21719019 has 8 divisors (see below), whose sum is σ = 33095680. Its totient is φ = 12410856.

The previous prime is 21718997. The next prime is 21719023. The reversal of 21719019 is 91091712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21719019 - 2⁷ = 21718891 is a prime.

It is a super-2 number, since 2×21719019² = 943431572644722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21719069) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 517099 + ... + 517140.

It is an arithmetic number, because the mean of its divisors is an integer number (4136960).

Almost surely, 2^21719019 is an apocalyptic number.

21719019 is a deficient number, since it is larger than the sum of its proper divisors (11376661).

21719019 is a wasteful number, since it uses less digits than its factorization.

21719019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1034249.

The product of its (nonzero) digits is 1134, while the sum is 30.

The square root of 21719019 is about 4660.3668310553. The cubic root of 21719019 is about 279.0059093570.

The spelling of 21719019 in words is "twenty-one million, seven hundred nineteen thousand, nineteen".