21936023 has 4 divisors (see below), whose sum is σ = 22307880. Its totient is φ = 21564168.

The previous prime is 21936017. The next prime is 21936037. The reversal of 21936023 is 32063912.

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

It is a cyclic number.

It is not a de Polignac number, because 21936023 - 2¹² = 21931927 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21935983 and 21936001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21936323) 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, 185840 + ... + 185957.

It is an arithmetic number, because the mean of its divisors is an integer number (5576970).

Almost surely, 2^21936023 is an apocalyptic number.

21936023 is a deficient number, since it is larger than the sum of its proper divisors (371857).

21936023 is an equidigital number, since it uses as much as digits as its factorization.

21936023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 371856.

The product of its (nonzero) digits is 1944, while the sum is 26.

The square root of 21936023 is about 4683.5908232893. The cubic root of 21936023 is about 279.9320540915.

Adding to 21936023 its reverse (32063912), we get a palindrome (53999935).

The spelling of 21936023 in words is "twenty-one million, nine hundred thirty-six thousand, twenty-three".