21221004143 has 4 divisors (see below), whose sum is σ = 21312081648. Its totient is φ = 21129926640.

The previous prime is 21221004131. The next prime is 21221004149. The reversal of 21221004143 is 34140012212.

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 21221004143 - 2¹⁴ = 21220987759 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221004149) 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, 45538403 + ... + 45538868.

It is an arithmetic number, because the mean of its divisors is an integer number (5328020412).

Almost surely, 2^21221004143 is an apocalyptic number.

21221004143 is a deficient number, since it is larger than the sum of its proper divisors (91077505).

21221004143 is an equidigital number, since it uses as much as digits as its factorization.

21221004143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91077504.

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 21221004143 its reverse (34140012212), we get a palindrome (55361016355).

The spelling of 21221004143 in words is "twenty-one billion, two hundred twenty-one million, four thousand, one hundred forty-three".