21983789 has 4 divisors (see below), whose sum is σ = 22210524. Its totient is φ = 21757056.

The previous prime is 21983747. The next prime is 21983807. The reversal of 21983789 is 98738912.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8219689 + 13764100 = 2867^2 + 3710^2 .

It is a cyclic number.

It is not a de Polignac number, because 21983789 - 2¹² = 21979693 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 (21980789) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 113222 + ... + 113415.

It is an arithmetic number, because the mean of its divisors is an integer number (5552631).

Almost surely, 2^21983789 is an apocalyptic number.

It is an amenable number.

21983789 is a deficient number, since it is larger than the sum of its proper divisors (226735).

21983789 is an equidigital number, since it uses as much as digits as its factorization.

21983789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226734.

The product of its digits is 217728, while the sum is 47.

The square root of 21983789 is about 4688.6873429564. The cubic root of 21983789 is about 280.1350921243.

The spelling of 21983789 in words is "twenty-one million, nine hundred eighty-three thousand, seven hundred eighty-nine".