212211665389421 has 2 divisors, whose sum is σ = 212211665389422. Its totient is φ = 212211665389420.

The previous prime is 212211665389387. The next prime is 212211665389453. The reversal of 212211665389421 is 124983566112212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 153129982684900 + 59081682704521 = 12374570^2 + 7686461^2 .

It is a cyclic number.

It is not a de Polignac number, because 212211665389421 - 2¹⁰ = 212211665388397 is a prime.

It is a super-3 number, since 3×212211665389421³ (a number of 44 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212211665389721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106105832694710 + 106105832694711.

It is an arithmetic number, because the mean of its divisors is an integer number (106105832694711).

Almost surely, 2^{212211665389421} is an apocalyptic number.

It is an amenable number.

212211665389421 is a deficient number, since it is larger than the sum of its proper divisors (1).

212211665389421 is an equidigital number, since it uses as much as digits as its factorization.

212211665389421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2488320, while the sum is 53.

The spelling of 212211665389421 in words is "two hundred twelve trillion, two hundred eleven billion, six hundred sixty-five million, three hundred eighty-nine thousand, four hundred twenty-one".