21719223 has 24 divisors (see below), whose sum is σ = 33274800. Its totient is φ = 13613184.

The previous prime is 21719219. The next prime is 21719237. The reversal of 21719223 is 32291712.

It is not a de Polignac number, because 21719223 - 2² = 21719219 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21719213) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 26443 + ... + 27251.

It is an arithmetic number, because the mean of its divisors is an integer number (1386450).

Almost surely, 2^21719223 is an apocalyptic number.

21719223 is a deficient number, since it is larger than the sum of its proper divisors (11555577).

21719223 is a wasteful number, since it uses less digits than its factorization.

21719223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 991 (or 988 counting only the distinct ones).

The product of its digits is 1512, while the sum is 27.

The square root of 21719223 is about 4660.3887176930. The cubic root of 21719223 is about 279.0067828929.

The spelling of 21719223 in words is "twenty-one million, seven hundred nineteen thousand, two hundred twenty-three".