8218138501 has 4 divisors (see below), whose sum is σ = 8373197772. Its totient is φ = 8063079232.

The previous prime is 8218138403. The next prime is 8218138519. The reversal of 8218138501 is 1058318128.

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 3594002500 + 4624136001 = 59950^2 + 68001^2 .

It is a cyclic number.

It is not a de Polignac number, because 8218138501 - 2⁹ = 8218137989 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 (8218133501) 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, 77529556 + ... + 77529661.

It is an arithmetic number, because the mean of its divisors is an integer number (2093299443).

Almost surely, 2^8218138501 is an apocalyptic number.

It is an amenable number.

8218138501 is a deficient number, since it is larger than the sum of its proper divisors (155059271).

8218138501 is a wasteful number, since it uses less digits than its factorization.

8218138501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155059270.

The product of its (nonzero) digits is 15360, while the sum is 37.

The square root of 8218138501 is about 90653.9491748705. The cubic root of 8218138501 is about 2018.0154430702.

The spelling of 8218138501 in words is "eight billion, two hundred eighteen million, one hundred thirty-eight thousand, five hundred one".