21719983 has 8 divisors (see below), whose sum is σ = 23295600. Its totient is φ = 20187648.

The previous prime is 21719959. The next prime is 21719989. The reversal of 21719983 is 38991712.

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 21719983 - 2²¹ = 19622831 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 (21719989) 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, 9778 + ... + 11791.

It is an arithmetic number, because the mean of its divisors is an integer number (2911950).

Almost surely, 2^21719983 is an apocalyptic number.

21719983 is a deficient number, since it is larger than the sum of its proper divisors (1575617).

21719983 is a wasteful number, since it uses less digits than its factorization.

21719983 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21641.

The product of its digits is 27216, while the sum is 40.

The square root of 21719983 is about 4660.4702552425. The cubic root of 21719983 is about 279.0100371941.

The spelling of 21719983 in words is "twenty-one million, seven hundred nineteen thousand, nine hundred eighty-three".