21752663 has 4 divisors (see below), whose sum is σ = 22897560. Its totient is φ = 20607768.

The previous prime is 21752657. The next prime is 21752699. The reversal of 21752663 is 36625712.

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 21752663 - 2²⁰ = 20704087 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 (21752603) 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, 572420 + ... + 572457.

It is an arithmetic number, because the mean of its divisors is an integer number (5724390).

Almost surely, 2^21752663 is an apocalyptic number.

21752663 is a deficient number, since it is larger than the sum of its proper divisors (1144897).

21752663 is a wasteful number, since it uses less digits than its factorization.

21752663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1144896.

The product of its digits is 15120, while the sum is 32.

The square root of 21752663 is about 4663.9750213739. The cubic root of 21752663 is about 279.1499003915.

The spelling of 21752663 in words is "twenty-one million, seven hundred fifty-two thousand, six hundred sixty-three".