215254140033221 has 4 divisors (see below), whose sum is σ = 215272233189612. Its totient is φ = 215236046876832.

The previous prime is 215254140033193. The next prime is 215254140033287. The reversal of 215254140033221 is 122330041452512.

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 199374823600225 + 15879316432996 = 14120015^2 + 3984886^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215254140033221 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 (215254140533221) 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, 9046560350 + ... + 9046584143.

It is an arithmetic number, because the mean of its divisors is an integer number (53818058297403).

Almost surely, 2^{215254140033221} is an apocalyptic number.

It is an amenable number.

215254140033221 is a deficient number, since it is larger than the sum of its proper divisors (18093156391).

215254140033221 is a wasteful number, since it uses less digits than its factorization.

215254140033221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18093156390.

The product of its (nonzero) digits is 57600, while the sum is 35.

Adding to 215254140033221 its reverse (122330041452512), we get a palindrome (337584181485733).

The spelling of 215254140033221 in words is "two hundred fifteen trillion, two hundred fifty-four billion, one hundred forty million, thirty-three thousand, two hundred twenty-one".