21523383 has 12 divisors (see below), whose sum is σ = 35530768. Its totient is φ = 12299040.

The previous prime is 21523361. The next prime is 21523387. The reversal of 21523383 is 38332512.

It is not a de Polignac number, because 21523383 - 2⁵ = 21523351 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21523387) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 170758 + ... + 170883.

Almost surely, 2^21523383 is an apocalyptic number.

21523383 is a deficient number, since it is larger than the sum of its proper divisors (14007385).

21523383 is a wasteful number, since it uses less digits than its factorization.

21523383 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 341654 (or 341651 counting only the distinct ones).

The product of its digits is 4320, while the sum is 27.

The square root of 21523383 is about 4639.3300162847. The cubic root of 21523383 is about 278.1656578696.

Adding to 21523383 its reverse (38332512), we get a palindrome (59855895).

It can be divided in two parts, 2 and 1523383, that added together give a triangular number (1523385 = T₁₇₄₅).

The spelling of 21523383 in words is "twenty-one million, five hundred twenty-three thousand, three hundred eighty-three".