21022613 has 8 divisors (see below), whose sum is σ = 21664536. Its totient is φ = 20390400.

The previous prime is 21022597. The next prime is 21022669. The reversal of 21022613 is 31622012.

It can be written as a sum of positive squares in 4 ways, for example, as 438244 + 20584369 = 662^2 + 4537^2 .

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 21022613 - 2⁴ = 21022597 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21022591 and 21022600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2093 + ... + 6813.

It is an arithmetic number, because the mean of its divisors is an integer number (2708067).

Almost surely, 2^21022613 is an apocalyptic number.

It is an amenable number.

21022613 is a deficient number, since it is larger than the sum of its proper divisors (641923).

21022613 is an equidigital number, since it uses as much as digits as its factorization.

21022613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4855.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 21022613 is about 4585.0423116914. The cubic root of 21022613 is about 275.9914099756.

Adding to 21022613 its reverse (31622012), we get a palindrome (52644625).

The spelling of 21022613 in words is "twenty-one million, twenty-two thousand, six hundred thirteen".