21022231 has 8 divisors (see below), whose sum is σ = 21450240. Its totient is φ = 20596728.

The previous prime is 21022223. The next prime is 21022249. The reversal of 21022231 is 13222012.

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 21022231 - 2³ = 21022223 is a prime.

It is a super-2 number, since 2×21022231² = 883868392434722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022271) 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, 34330 + ... + 34936.

It is an arithmetic number, because the mean of its divisors is an integer number (2681280).

Almost surely, 2^21022231 is an apocalyptic number.

21022231 is a deficient number, since it is larger than the sum of its proper divisors (428009).

21022231 is an equidigital number, since it uses as much as digits as its factorization.

21022231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1253.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21022231 is about 4585.0006543075. Note that the first 3 decimals coincide. The cubic root of 21022231 is about 275.9897382938.

Adding to 21022231 its reverse (13222012), we get a palindrome (34244243).

The spelling of 21022231 in words is "twenty-one million, twenty-two thousand, two hundred thirty-one".