212021121643 has 2 divisors, whose sum is σ = 212021121644. Its totient is φ = 212021121642.

The previous prime is 212021121617. The next prime is 212021121661. The reversal of 212021121643 is 346121120212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 212021121643 - 2⁹ = 212021121131 is a prime.

It is not a weakly prime, because it can be changed into another prime (212021121343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106010560821 + 106010560822.

It is an arithmetic number, because the mean of its divisors is an integer number (106010560822).

Almost surely, 2^212021121643 is an apocalyptic number.

212021121643 is a deficient number, since it is larger than the sum of its proper divisors (1).

212021121643 is an equidigital number, since it uses as much as digits as its factorization.

212021121643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 25.

Adding to 212021121643 its reverse (346121120212), we get a palindrome (558142241855).

The spelling of 212021121643 in words is "two hundred twelve billion, twenty-one million, one hundred twenty-one thousand, six hundred forty-three".