211431400021 has 4 divisors (see below), whose sum is σ = 211433305612. Its totient is φ = 211429494432.

The previous prime is 211431400013. The next prime is 211431400073. The reversal of 211431400021 is 120004134112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 105667254225 + 105764145796 = 325065^2 + 325214^2 .

It is a cyclic number.

It is not a de Polignac number, because 211431400021 - 2³ = 211431400013 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 (211431400001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 775350 + ... + 1011943.

It is an arithmetic number, because the mean of its divisors is an integer number (52858326403).

Almost surely, 2^211431400021 is an apocalyptic number.

It is an amenable number.

211431400021 is a deficient number, since it is larger than the sum of its proper divisors (1905591).

211431400021 is a wasteful number, since it uses less digits than its factorization.

211431400021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1905590.

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 211431400021 its reverse (120004134112), we get a palindrome (331435534133).

The spelling of 211431400021 in words is "two hundred eleven billion, four hundred thirty-one million, four hundred thousand, twenty-one".