21220023 has 8 divisors (see below), whose sum is σ = 30865536. Its totient is φ = 12860600.

The previous prime is 21220019. The next prime is 21220103. The reversal of 21220023 is 32002212.

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 21220023 - 2² = 21220019 is a prime.

It is a super-2 number, since 2×21220023² = 900578752241058, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21219990 and 21220008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220223) 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, 321483 + ... + 321548.

It is an arithmetic number, because the mean of its divisors is an integer number (3858192).

Almost surely, 2^21220023 is an apocalyptic number.

21220023 is a deficient number, since it is larger than the sum of its proper divisors (9645513).

21220023 is a wasteful number, since it uses less digits than its factorization.

21220023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643045.

The product of its (nonzero) digits is 48, while the sum is 12.

The square root of 21220023 is about 4606.5196189748. The cubic root of 21220023 is about 276.8526065759.

Adding to 21220023 its reverse (32002212), we get a palindrome (53222235).

The spelling of 21220023 in words is "twenty-one million, two hundred twenty thousand, twenty-three".