8221636429 has 4 divisors (see below), whose sum is σ = 8240624476. Its totient is φ = 8202648384.

The previous prime is 8221636399. The next prime is 8221636453. The reversal of 8221636429 is 9246361228.

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 4938575625 + 3283060804 = 70275^2 + 57298^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8221636429 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 (8221636469) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9493374 + ... + 9494239.

It is an arithmetic number, because the mean of its divisors is an integer number (2060156119).

Almost surely, 2^8221636429 is an apocalyptic number.

It is an amenable number.

8221636429 is a deficient number, since it is larger than the sum of its proper divisors (18988047).

8221636429 is a wasteful number, since it uses less digits than its factorization.

8221636429 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18988046.

The product of its digits is 248832, while the sum is 43.

The square root of 8221636429 is about 90673.2398726328. The cubic root of 8221636429 is about 2018.3017151766.

The spelling of 8221636429 in words is "eight billion, two hundred twenty-one million, six hundred thirty-six thousand, four hundred twenty-nine".