211421421 has 12 divisors (see below), whose sum is σ = 316697472. Its totient is φ = 140947452.

The previous prime is 211421387. The next prime is 211421437. The reversal of 211421421 is 124124112.

It is not a de Polignac number, because 211421421 - 2¹³ = 211413229 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 211421394 and 211421403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211421321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 434781 + ... + 435266.

It is an arithmetic number, because the mean of its divisors is an integer number (26391456).

Almost surely, 2^211421421 is an apocalyptic number.

It is an amenable number.

211421421 is a deficient number, since it is larger than the sum of its proper divisors (105276051).

211421421 is an frugal number, since it uses more digits than its factorization.

211421421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 870062 (or 870050 counting only the distinct ones).

The product of its digits is 128, while the sum is 18.

The square root of 211421421 is about 14540.3377195992. The cubic root of 211421421 is about 595.7302626457.

Adding to 211421421 its reverse (124124112), we get a palindrome (335545533).

The spelling of 211421421 in words is "two hundred eleven million, four hundred twenty-one thousand, four hundred twenty-one".