211355315426021 has 4 divisors (see below), whose sum is σ = 227613416612652. Its totient is φ = 195097214239392.

The previous prime is 211355315425987. The next prime is 211355315426027. The reversal of 211355315426021 is 120624513553112.

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 21579508890625 + 189775806535396 = 4645375^2 + 13775914^2 .

It is a cyclic number.

It is not a de Polignac number, because 211355315426021 - 2¹⁰ = 211355315424997 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 211355315426021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211355315426027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8129050593296 + ... + 8129050593321.

It is an arithmetic number, because the mean of its divisors is an integer number (56903354153163).

Almost surely, 2^{211355315426021} is an apocalyptic number.

It is an amenable number.

211355315426021 is a deficient number, since it is larger than the sum of its proper divisors (16258101186631).

211355315426021 is a wasteful number, since it uses less digits than its factorization.

211355315426021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16258101186630.

The product of its (nonzero) digits is 216000, while the sum is 41.

Adding to 211355315426021 its reverse (120624513553112), we get a palindrome (331979828979133).

The spelling of 211355315426021 in words is "two hundred eleven trillion, three hundred fifty-five billion, three hundred fifteen million, four hundred twenty-six thousand, twenty-one".