8497788221 has 4 divisors (see below), whose sum is σ = 9151464252. Its totient is φ = 7844112192.

The previous prime is 8497788197. The next prime is 8497788223. The reversal of 8497788221 is 1228877948.

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 2607225721 + 5890562500 = 51061^2 + 76750^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8497788221 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 (8497788223) 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, 326837996 + ... + 326838021.

It is an arithmetic number, because the mean of its divisors is an integer number (2287866063).

Almost surely, 2^8497788221 is an apocalyptic number.

It is an amenable number.

8497788221 is a deficient number, since it is larger than the sum of its proper divisors (653676031).

8497788221 is a wasteful number, since it uses less digits than its factorization.

8497788221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 653676030.

The product of its digits is 3612672, while the sum is 56.

The square root of 8497788221 is about 92183.4487367445. The cubic root of 8497788221 is about 2040.6505215041.

The spelling of 8497788221 in words is "eight billion, four hundred ninety-seven million, seven hundred eighty-eight thousand, two hundred twenty-one".