212021055391 has 2 divisors, whose sum is σ = 212021055392. Its totient is φ = 212021055390.

The previous prime is 212021055377. The next prime is 212021055397. The reversal of 212021055391 is 193550120212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 212021055391 - 2⁹ = 212021054879 is a prime.

It is a super-2 number, since 2×212021055391² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212021055397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106010527695 + 106010527696.

It is an arithmetic number, because the mean of its divisors is an integer number (106010527696).

Almost surely, 2^212021055391 is an apocalyptic number.

212021055391 is a deficient number, since it is larger than the sum of its proper divisors (1).

212021055391 is an equidigital number, since it uses as much as digits as its factorization.

212021055391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5400, while the sum is 31.

The spelling of 212021055391 in words is "two hundred twelve billion, twenty-one million, fifty-five thousand, three hundred ninety-one".