21873719 has 8 divisors (see below), whose sum is σ = 25422720. Its totient is φ = 18430776.

The previous prime is 21873707. The next prime is 21873721. The reversal of 21873719 is 91737812.

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

It is a de Polignac number, because none of the positive numbers 2^k-21873719 is a prime.

It is a super-2 number, since 2×21873719² = 956919165781922, 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 (21873739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26069 + ... + 26894.

It is an arithmetic number, because the mean of its divisors is an integer number (3177840).

Almost surely, 2^21873719 is an apocalyptic number.

21873719 is a deficient number, since it is larger than the sum of its proper divisors (3549001).

21873719 is an equidigital number, since it uses as much as digits as its factorization.

21873719 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53029.

The product of its digits is 21168, while the sum is 38.

The square root of 21873719 is about 4676.9347868021. The cubic root of 21873719 is about 279.6667762117. Note that the first 3 decimals are identical.

It can be divided in two parts, 218 and 73719, that added together give a palindrome (73937).

The spelling of 21873719 in words is "twenty-one million, eight hundred seventy-three thousand, seven hundred nineteen".