212021110421 has 2 divisors, whose sum is σ = 212021110422. Its totient is φ = 212021110420.

The previous prime is 212021110393. The next prime is 212021110439. The reversal of 212021110421 is 124011120212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 210943629796 + 1077480625 = 459286^2 + 32825^2 .

It is a cyclic number.

It is not a de Polignac number, because 212021110421 - 2²⁶ = 211954001557 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 212021110421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212021110321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106010555210 + 106010555211.

It is an arithmetic number, because the mean of its divisors is an integer number (106010555211).

Almost surely, 2^212021110421 is an apocalyptic number.

It is an amenable number.

212021110421 is a deficient number, since it is larger than the sum of its proper divisors (1).

212021110421 is an equidigital number, since it uses as much as digits as its factorization.

212021110421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 212021110421 its reverse (124011120212), we get a palindrome (336032230633).

The spelling of 212021110421 in words is "two hundred twelve billion, twenty-one million, one hundred ten thousand, four hundred twenty-one".