215652210021 has 12 divisors (see below), whose sum is σ = 311503152480. Its totient is φ = 143765594280.

The previous prime is 215652209893. The next prime is 215652210049. The reversal of 215652210021 is 120012256512.

215652210021 is a `hidden beast` number, since 2 + 1 + 5 + 652 + 2 + 1 + 0 + 0 + 2 + 1 = 666.

It is not a de Polignac number, because 215652210021 - 2⁷ = 215652209893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215652210071) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 425106 + ... + 782316.

It is an arithmetic number, because the mean of its divisors is an integer number (25958596040).

Almost surely, 2^215652210021 is an apocalyptic number.

It is an amenable number.

215652210021 is a deficient number, since it is larger than the sum of its proper divisors (95850942459).

215652210021 is a wasteful number, since it uses less digits than its factorization.

215652210021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 424296 (or 424293 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

Adding to 215652210021 its reverse (120012256512), we get a palindrome (335664466533).

The spelling of 215652210021 in words is "two hundred fifteen billion, six hundred fifty-two million, two hundred ten thousand, twenty-one".