212011221220021 has 4 divisors (see below), whose sum is σ = 212013806584032. Its totient is φ = 212008635856012.

The previous prime is 212011221219997. The next prime is 212011221220031. The reversal of 212011221220021 is 120022122110212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 212011221220021 - 2¹⁵ = 212011221187253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212011221220031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1292558995 + ... + 1292723008.

It is an arithmetic number, because the mean of its divisors is an integer number (53003451646008).

Almost surely, 2^{212011221220021} is an apocalyptic number.

It is an amenable number.

212011221220021 is a deficient number, since it is larger than the sum of its proper divisors (2585364011).

212011221220021 is an equidigital number, since it uses as much as digits as its factorization.

212011221220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2585364010.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 212011221220021 its reverse (120022122110212), we get a palindrome (332033343330233).

The spelling of 212011221220021 in words is "two hundred twelve trillion, eleven billion, two hundred twenty-one million, two hundred twenty thousand, twenty-one".