215231362212821 has 2 divisors, whose sum is σ = 215231362212822. Its totient is φ = 215231362212820.

The previous prime is 215231362212791. The next prime is 215231362212847. The reversal of 215231362212821 is 128212263132512.

215231362212821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 213715570332196 + 1515791880625 = 14619014^2 + 1231175^2 .

It is a cyclic number.

It is not a de Polignac number, because 215231362212821 - 2³⁰ = 215230288470997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215231362211821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107615681106410 + 107615681106411.

It is an arithmetic number, because the mean of its divisors is an integer number (107615681106411).

Almost surely, 2^{215231362212821} is an apocalyptic number.

It is an amenable number.

215231362212821 is a deficient number, since it is larger than the sum of its proper divisors (1).

215231362212821 is an equidigital number, since it uses as much as digits as its factorization.

215231362212821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 138240, while the sum is 41.

The spelling of 215231362212821 in words is "two hundred fifteen trillion, two hundred thirty-one billion, three hundred sixty-two million, two hundred twelve thousand, eight hundred twenty-one".