8400660221 has 4 divisors (see below), whose sum is σ = 8420151744. Its totient is φ = 8381168700.

The previous prime is 8400660217. The next prime is 8400660223. The reversal of 8400660221 is 1220660048.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 8400660221 - 2² = 8400660217 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 (8400660223) 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, 9745115 + ... + 9745976.

It is an arithmetic number, because the mean of its divisors is an integer number (2105037936).

Almost surely, 2^8400660221 is an apocalyptic number.

It is an amenable number.

8400660221 is a deficient number, since it is larger than the sum of its proper divisors (19491523).

8400660221 is a wasteful number, since it uses less digits than its factorization.

8400660221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19491522.

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 8400660221 is about 91655.1156291890. The cubic root of 8400660221 is about 2032.8459698709.

The spelling of 8400660221 in words is "eight billion, four hundred million, six hundred sixty thousand, two hundred twenty-one".