211212131330021 has 16 divisors (see below), whose sum is σ = 223939932398640. Its totient is φ = 198518081556480.

The previous prime is 211212131329981. The next prime is 211212131330029. The reversal of 211212131330021 is 120033131212112.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 14991261141025 + 196220870188996 = 3871855^2 + 14007886^2 .

It is a cyclic number.

It is not a de Polignac number, because 211212131330021 - 2²² = 211212127135717 is a prime.

It is a super-2 number, since 2×211212131330021² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211212131330029) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 309228335 + ... + 309910611.

It is an arithmetic number, because the mean of its divisors is an integer number (13996245774915).

Almost surely, 2^{211212131330021} is an apocalyptic number.

It is an amenable number.

211212131330021 is a deficient number, since it is larger than the sum of its proper divisors (12727801068619).

211212131330021 is a wasteful number, since it uses less digits than its factorization.

211212131330021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 706984.

The product of its (nonzero) digits is 432, while the sum is 23.

Adding to 211212131330021 its reverse (120033131212112), we get a palindrome (331245262542133).

The spelling of 211212131330021 in words is "two hundred eleven trillion, two hundred twelve billion, one hundred thirty-one million, three hundred thirty thousand, twenty-one".