21221000023 has 4 divisors (see below), whose sum is σ = 22469294160. Its totient is φ = 19972705888.

The previous prime is 21220999973. The next prime is 21221000027. The reversal of 21221000023 is 32000012212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21221000023 - 2¹⁷ = 21220868951 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21220999967 and 21221000012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221000027) 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, 624147043 + ... + 624147076.

It is an arithmetic number, because the mean of its divisors is an integer number (5617323540).

Almost surely, 2^21221000023 is an apocalyptic number.

21221000023 is a deficient number, since it is larger than the sum of its proper divisors (1248294137).

21221000023 is a wasteful number, since it uses less digits than its factorization.

21221000023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1248294136.

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

Adding to 21221000023 its reverse (32000012212), we get a palindrome (53221012235).

The spelling of 21221000023 in words is "twenty-one billion, two hundred twenty-one million, twenty-three", and thus it is an aban number.