6636221420 has 24 divisors (see below), whose sum is σ = 13938102864. Its totient is φ = 2654100416.

The previous prime is 6636221413. The next prime is 6636221443. The reversal of 6636221420 is 241226366.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 144599 + ... + 184881.

It is an arithmetic number, because the mean of its divisors is an integer number (580754286).

Almost surely, 2^6636221420 is an apocalyptic number.

It is an amenable number.

6636221420 is an abundant number, since it is smaller than the sum of its proper divisors (7301881444).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6636221420 is a wasteful number, since it uses less digits than its factorization.

6636221420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48529 (or 48527 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 32.

The square root of 6636221420 is about 81463.0064507811. The cubic root of 6636221420 is about 1879.2026779682.

Adding to 6636221420 its reverse (241226366), we get a palindrome (6877447786).

The spelling of 6636221420 in words is "six billion, six hundred thirty-six million, two hundred twenty-one thousand, four hundred twenty".