4221686538 has 48 divisors (see below), whose sum is σ = 9205578720. Its totient is φ = 1398246048.

The previous prime is 4221686537. The next prime is 4221686543. The reversal of 4221686538 is 8356861224.

4221686538 is a `hidden beast` number, since 4 + 22 + 16 + 86 + 538 = 666.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 4221686493 and 4221686502.

It is not an unprimeable number, because it can be changed into a prime (4221686537) 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 23 ways as a sum of consecutive naturals, for example, 2260281 + ... + 2262147.

It is an arithmetic number, because the mean of its divisors is an integer number (191782890).

Almost surely, 2^4221686538 is an apocalyptic number.

4221686538 is an abundant number, since it is smaller than the sum of its proper divisors (4983892182).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

4221686538 is a wasteful number, since it uses less digits than its factorization.

4221686538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2611 (or 2608 counting only the distinct ones).

The product of its digits is 552960, while the sum is 45.

The square root of 4221686538 is about 64974.5068315259. The cubic root of 4221686538 is about 1616.2008389753.

It can be divided in two parts, 4221686 and 538, that added together give a palindrome (4222224).

The spelling of 4221686538 in words is "four billion, two hundred twenty-one million, six hundred eighty-six thousand, five hundred thirty-eight".