211421023421 has 4 divisors (see below), whose sum is σ = 214576561152. Its totient is φ = 208265485692.

The previous prime is 211421023343. The next prime is 211421023459. The reversal of 211421023421 is 124320124112.

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 211421023421 - 2³⁰ = 210347281597 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 (211421023321) 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, 1577768765 + ... + 1577768898.

It is an arithmetic number, because the mean of its divisors is an integer number (53644140288).

Almost surely, 2^211421023421 is an apocalyptic number.

It is an amenable number.

211421023421 is a deficient number, since it is larger than the sum of its proper divisors (3155537731).

211421023421 is an equidigital number, since it uses as much as digits as its factorization.

211421023421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3155537730.

The product of its (nonzero) digits is 768, while the sum is 23.

Adding to 211421023421 its reverse (124320124112), we get a palindrome (335741147533).

The spelling of 211421023421 in words is "two hundred eleven billion, four hundred twenty-one million, twenty-three thousand, four hundred twenty-one".