21793423 has 4 divisors (see below), whose sum is σ = 21816280. Its totient is φ = 21770568.

The previous prime is 21793363. The next prime is 21793451. The reversal of 21793423 is 32439712.

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 21793423 - 2¹⁷ = 21662351 is a prime.

It is a super-3 number, since 3×21793423³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21793463) 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, 9933 + ... + 11926.

It is an arithmetic number, because the mean of its divisors is an integer number (5454070).

Almost surely, 2^21793423 is an apocalyptic number.

21793423 is a deficient number, since it is larger than the sum of its proper divisors (22857).

21793423 is an equidigital number, since it uses as much as digits as its factorization.

21793423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22856.

The product of its digits is 9072, while the sum is 31.

The square root of 21793423 is about 4668.3426395242. The cubic root of 21793423 is about 279.3241480313.

The spelling of 21793423 in words is "twenty-one million, seven hundred ninety-three thousand, four hundred twenty-three".