21983245 has 8 divisors (see below), whose sum is σ = 26424216. Its totient is φ = 17557056.

The previous prime is 21983237. The next prime is 21983281. The reversal of 21983245 is 54238912.

It can be written as a sum of positive squares in 4 ways, for example, as 5750404 + 16232841 = 2398^2 + 4029^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21983245 - 2³ = 21983237 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21983245.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 102 + ... + 6631.

It is an arithmetic number, because the mean of its divisors is an integer number (3303027).

Almost surely, 2^21983245 is an apocalyptic number.

It is an amenable number.

21983245 is a deficient number, since it is larger than the sum of its proper divisors (4440971).

21983245 is an equidigital number, since it uses as much as digits as its factorization.

21983245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7391.

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

The square root of 21983245 is about 4688.6293306253. The cubic root of 21983245 is about 280.1327814103.

It can be divided in two parts, 21983 and 245, that multiplied together give a palindrome (5385835).

The spelling of 21983245 in words is "twenty-one million, nine hundred eighty-three thousand, two hundred forty-five".