215266401621 has 6 divisors (see below), whose sum is σ = 310940357910. Its totient is φ = 143510934408.

The previous prime is 215266401613. The next prime is 215266401667. The reversal of 215266401621 is 126104662512.

215266401621 is a `hidden beast` number, since 2 + 1 + 5 + 2 + 6 + 640 + 1 + 6 + 2 + 1 = 666.

215266401621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 200748802500 + 14517599121 = 448050^2 + 120489^2 .

It is not a de Polignac number, because 215266401621 - 2³ = 215266401613 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215266401421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11959244526 + ... + 11959244543.

It is an arithmetic number, because the mean of its divisors is an integer number (51823392985).

Almost surely, 2^215266401621 is an apocalyptic number.

It is an amenable number.

215266401621 is a deficient number, since it is larger than the sum of its proper divisors (95673956289).

215266401621 is a wasteful number, since it uses less digits than its factorization.

215266401621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23918489075 (or 23918489072 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The spelling of 215266401621 in words is "two hundred fifteen billion, two hundred sixty-six million, four hundred one thousand, six hundred twenty-one".