211431444021 has 72 divisors (see below), whose sum is σ = 381124991520. Its totient is φ = 116651640672.

The previous prime is 211431444019. The next prime is 211431444043. The reversal of 211431444021 is 120444134112.

211431444021 is a `hidden beast` number, since 2 + 114 + 3 + 144 + 402 + 1 = 666.

It is not a de Polignac number, because 211431444021 - 2¹ = 211431444019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211431444011) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 39150 + ... + 651456.

It is an arithmetic number, because the mean of its divisors is an integer number (5293402660).

Almost surely, 2^211431444021 is an apocalyptic number.

211431444021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

211431444021 is a deficient number, since it is larger than the sum of its proper divisors (169693547499).

211431444021 is an equidigital number, since it uses as much as digits as its factorization.

211431444021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 612365 (or 612346 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

Adding to 211431444021 its reverse (120444134112), we get a palindrome (331875578133).

The spelling of 211431444021 in words is "two hundred eleven billion, four hundred thirty-one million, four hundred forty-four thousand, twenty-one".