21143142221 has 12 divisors (see below), whose sum is σ = 22335943644. Its totient is φ = 20011104000.

The previous prime is 21143142217. The next prime is 21143142239. The reversal of 21143142221 is 12224134112.

It can be written as a sum of positive squares in 2 ways, for example, as 5979928900 + 15163213321 = 77330^2 + 123139^2 .

It is not a de Polignac number, because 21143142221 - 2² = 21143142217 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 (21143142281) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 355421 + ... + 410621.

It is an arithmetic number, because the mean of its divisors is an integer number (1861328637).

Almost surely, 2^21143142221 is an apocalyptic number.

It is an amenable number.

21143142221 is a deficient number, since it is larger than the sum of its proper divisors (1192801423).

21143142221 is a wasteful number, since it uses less digits than its factorization.

21143142221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56300 (or 56281 counting only the distinct ones).

The product of its digits is 768, while the sum is 23.

Adding to 21143142221 its reverse (12224134112), we get a palindrome (33367276333).

The spelling of 21143142221 in words is "twenty-one billion, one hundred forty-three million, one hundred forty-two thousand, two hundred twenty-one".