8147238221 has 4 divisors (see below), whose sum is σ = 8428177500. Its totient is φ = 7866298944.

The previous prime is 8147238217. The next prime is 8147238233. The reversal of 8147238221 is 1228327418.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1522092196 + 6625146025 = 39014^2 + 81395^2 .

It is a cyclic number.

It is not a de Polignac number, because 8147238221 - 2² = 8147238217 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 (8147238271) 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, 140469596 + ... + 140469653.

It is an arithmetic number, because the mean of its divisors is an integer number (2107044375).

Almost surely, 2^8147238221 is an apocalyptic number.

It is an amenable number.

8147238221 is a deficient number, since it is larger than the sum of its proper divisors (280939279).

8147238221 is a wasteful number, since it uses less digits than its factorization.

8147238221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280939278.

The product of its digits is 43008, while the sum is 38.

The square root of 8147238221 is about 90262.0530511023. The cubic root of 8147238221 is about 2012.1953374747.

The spelling of 8147238221 in words is "eight billion, one hundred forty-seven million, two hundred thirty-eight thousand, two hundred twenty-one".