21719869 has 8 divisors (see below), whose sum is σ = 23652000. Its totient is φ = 19866672.

The previous prime is 21719861. The next prime is 21719881. The reversal of 21719869 is 96891712.

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

It is a cyclic number.

It is not a de Polignac number, because 21719869 - 2³ = 21719861 is a prime.

It is a super-2 number, since 2×21719869² = 943505418754322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21719861) 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, 19159 + ... + 20260.

It is an arithmetic number, because the mean of its divisors is an integer number (2956500).

Almost surely, 2^21719869 is an apocalyptic number.

21719869 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

21719869 is a deficient number, since it is larger than the sum of its proper divisors (1932131).

21719869 is a wasteful number, since it uses less digits than its factorization.

21719869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39467.

The product of its digits is 54432, while the sum is 43.

The square root of 21719869 is about 4660.4580247010. The cubic root of 21719869 is about 279.0095490537.

The spelling of 21719869 in words is "twenty-one million, seven hundred nineteen thousand, eight hundred sixty-nine".