21919837 has 8 divisors (see below), whose sum is σ = 22255200. Its totient is φ = 21587280.

The previous prime is 21919831. The next prime is 21919847. The reversal of 21919837 is 73891912.

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 21919837 - 2¹¹ = 21917789 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 12.

It is a self number, because there is not a number n which added to its sum of digits gives 21919837.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21919831) 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, 18958 + ... + 20080.

It is an arithmetic number, because the mean of its divisors is an integer number (2781900).

Almost surely, 2^21919837 is an apocalyptic number.

It is an amenable number.

21919837 is a deficient number, since it is larger than the sum of its proper divisors (335363).

21919837 is a wasteful number, since it uses less digits than its factorization.

21919837 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1403.

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

The square root of 21919837 is about 4681.8625567182. The cubic root of 21919837 is about 279.8631857114.

The spelling of 21919837 in words is "twenty-one million, nine hundred nineteen thousand, eight hundred thirty-seven".