21301020233821 has 2 divisors, whose sum is σ = 21301020233822. Its totient is φ = 21301020233820.

The previous prime is 21301020233819. The next prime is 21301020233833. The reversal of 21301020233821 is 12833202010312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19956322562500 + 1344697671321 = 4467250^2 + 1159611^2 .

It is a cyclic number.

It is not a de Polignac number, because 21301020233821 - 2¹ = 21301020233819 is a prime.

Together with 21301020233819, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21301020233821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21301020233851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10650510116910 + 10650510116911.

It is an arithmetic number, because the mean of its divisors is an integer number (10650510116911).

Almost surely, 2^{21301020233821} is an apocalyptic number.

It is an amenable number.

21301020233821 is a deficient number, since it is larger than the sum of its proper divisors (1).

21301020233821 is an equidigital number, since it uses as much as digits as its factorization.

21301020233821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 28.

The spelling of 21301020233821 in words is "twenty-one trillion, three hundred one billion, twenty million, two hundred thirty-three thousand, eight hundred twenty-one".