21022361 has 8 divisors (see below), whose sum is σ = 21834120. Its totient is φ = 20216448.

The previous prime is 21022357. The next prime is 21022363. The reversal of 21022361 is 16322012.

It can be written as a sum of positive squares in 4 ways, for example, as 5569600 + 15452761 = 2360^2 + 3931^2 .

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 21022361 - 2² = 21022357 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21022363) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6725 + ... + 9341.

It is an arithmetic number, because the mean of its divisors is an integer number (2729265).

Almost surely, 2^21022361 is an apocalyptic number.

It is an amenable number.

21022361 is a deficient number, since it is larger than the sum of its proper divisors (811759).

21022361 is a wasteful number, since it uses less digits than its factorization.

21022361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2923.

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

The square root of 21022361 is about 4585.0148309466. The cubic root of 21022361 is about 275.9903071930.

Adding to 21022361 its reverse (16322012), we get a palindrome (37344373).

The spelling of 21022361 in words is "twenty-one million, twenty-two thousand, three hundred sixty-one".