21142119821 has 2 divisors, whose sum is σ = 21142119822. Its totient is φ = 21142119820.

The previous prime is 21142119811. The next prime is 21142119827. The reversal of 21142119821 is 12891124112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18984981796 + 2157138025 = 137786^2 + 46445^2 .

It is a cyclic number.

It is not a de Polignac number, because 21142119821 - 2¹⁸ = 21141857677 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21142119827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10571059910 + 10571059911.

It is an arithmetic number, because the mean of its divisors is an integer number (10571059911).

Almost surely, 2^21142119821 is an apocalyptic number.

It is an amenable number.

21142119821 is a deficient number, since it is larger than the sum of its proper divisors (1).

21142119821 is an equidigital number, since it uses as much as digits as its factorization.

21142119821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2304, while the sum is 32.

The spelling of 21142119821 in words is "twenty-one billion, one hundred forty-two million, one hundred nineteen thousand, eight hundred twenty-one".