21142330021 has 2 divisors, whose sum is σ = 21142330022. Its totient is φ = 21142330020.

The previous prime is 21142330019. The next prime is 21142330037. The reversal of 21142330021 is 12003324112.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20423553921 + 718776100 = 142911^2 + 26810^2 .

It is a cyclic number.

It is not a de Polignac number, because 21142330021 - 2¹ = 21142330019 is a prime.

Together with 21142330019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21142330421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10571165010 + 10571165011.

It is an arithmetic number, because the mean of its divisors is an integer number (10571165011).

Almost surely, 2^21142330021 is an apocalyptic number.

It is an amenable number.

21142330021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21142330021 is an equidigital number, since it uses as much as digits as its factorization.

21142330021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21142330021 its reverse (12003324112), we get a palindrome (33145654133).

The spelling of 21142330021 in words is "twenty-one billion, one hundred forty-two million, three hundred thirty thousand, twenty-one".