212131421 has 2 divisors, whose sum is σ = 212131422. Its totient is φ = 212131420.

The previous prime is 212131399. The next prime is 212131453. The reversal of 212131421 is 124131212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 199092100 + 13039321 = 14110^2 + 3611^2 .

It is a cyclic number.

It is not a de Polignac number, because 212131421 - 2¹⁰ = 212130397 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 212131421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212133421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106065710 + 106065711.

It is an arithmetic number, because the mean of its divisors is an integer number (106065711).

Almost surely, 2^212131421 is an apocalyptic number.

It is an amenable number.

212131421 is a deficient number, since it is larger than the sum of its proper divisors (1).

212131421 is an equidigital number, since it uses as much as digits as its factorization.

212131421 is an evil number, because the sum of its binary digits is even.

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

The square root of 212131421 is about 14564.7320950301. The cubic root of 212131421 is about 596.3963823036.

Adding to 212131421 its reverse (124131212), we get a palindrome (336262633).

The spelling of 212131421 in words is "two hundred twelve million, one hundred thirty-one thousand, four hundred twenty-one".