21982613 has 4 divisors (see below), whose sum is σ = 22087008. Its totient is φ = 21878220.

The previous prime is 21982603. The next prime is 21982621. The reversal of 21982613 is 31628912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21982613 - 2¹⁸ = 21720469 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21982613.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21982603) 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, 51881 + ... + 52302.

It is an arithmetic number, because the mean of its divisors is an integer number (5521752).

Almost surely, 2^21982613 is an apocalyptic number.

It is an amenable number.

21982613 is a deficient number, since it is larger than the sum of its proper divisors (104395).

21982613 is a wasteful number, since it uses less digits than its factorization.

21982613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104394.

The product of its digits is 5184, while the sum is 32.

The square root of 21982613 is about 4688.5619330451. The cubic root of 21982613 is about 280.1300968564.

The spelling of 21982613 in words is "twenty-one million, nine hundred eighty-two thousand, six hundred thirteen".