815265210221 has 16 divisors (see below), whose sum is σ = 1035612563328. Its totient is φ = 623285332800.

The previous prime is 815265210211. The next prime is 815265210233. The reversal of 815265210221 is 122012562518.

It is a cyclic number.

It is not a de Polignac number, because 815265210221 - 2³⁰ = 814191468397 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (815265210211) 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, 99881390 + ... + 99889551.

It is an arithmetic number, because the mean of its divisors is an integer number (64725785208).

Almost surely, 2^815265210221 is an apocalyptic number.

It is an amenable number.

815265210221 is a deficient number, since it is larger than the sum of its proper divisors (220347353107).

815265210221 is a wasteful number, since it uses less digits than its factorization.

815265210221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199771012.

The product of its (nonzero) digits is 19200, while the sum is 35.

Adding to 815265210221 its reverse (122012562518), we get a palindrome (937277772739).

The spelling of 815265210221 in words is "eight hundred fifteen billion, two hundred sixty-five million, two hundred ten thousand, two hundred twenty-one".