211231421 has 4 divisors (see below), whose sum is σ = 211267200. Its totient is φ = 211195644.

The previous prime is 211231403. The next prime is 211231429. The reversal of 211231421 is 124132112.

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 a de Polignac number, because none of the positive numbers 2^k-211231421 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 211231421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211231429) 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, 6701 + ... + 21618.

It is an arithmetic number, because the mean of its divisors is an integer number (52816800).

Almost surely, 2^211231421 is an apocalyptic number.

It is an amenable number.

211231421 is a deficient number, since it is larger than the sum of its proper divisors (35779).

211231421 is an equidigital number, since it uses as much as digits as its factorization.

211231421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35778.

The product of its digits is 96, while the sum is 17.

The square root of 211231421 is about 14533.8027026653. The cubic root of 211231421 is about 595.5517523934.

Adding to 211231421 its reverse (124132112), we get a palindrome (335363533).

It can be divided in two parts, 2112 and 31421, that added together give a palindrome (33533).

The spelling of 211231421 in words is "two hundred eleven million, two hundred thirty-one thousand, four hundred twenty-one".