21245983 has 4 divisors (see below), whose sum is σ = 23177448. Its totient is φ = 19314520.

The previous prime is 21245981. The next prime is 21246053. The reversal of 21245983 is 38954212.

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 21245983 - 2¹ = 21245981 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 (21245981) 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, 965716 + ... + 965737.

It is an arithmetic number, because the mean of its divisors is an integer number (5794362).

Almost surely, 2^21245983 is an apocalyptic number.

21245983 is a deficient number, since it is larger than the sum of its proper divisors (1931465).

21245983 is a wasteful number, since it uses less digits than its factorization.

21245983 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1931464.

The product of its digits is 17280, while the sum is 34.

The square root of 21245983 is about 4609.3365032291. The cubic root of 21245983 is about 276.9654585557.

The spelling of 21245983 in words is "twenty-one million, two hundred forty-five thousand, nine hundred eighty-three".