21221122018 has 8 divisors (see below), whose sum is σ = 31982544720. Its totient is φ = 10560273780.

The previous prime is 21221121991. The next prime is 21221122061. The reversal of 21221122018 is 81022112212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21221122018.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25143088 + ... + 25143931.

It is an arithmetic number, because the mean of its divisors is an integer number (3997818090).

Almost surely, 2^21221122018 is an apocalyptic number.

21221122018 is a deficient number, since it is larger than the sum of its proper divisors (10761422702).

21221122018 is a wasteful number, since it uses less digits than its factorization.

21221122018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50287232.

The product of its (nonzero) digits is 256, while the sum is 22.

The spelling of 21221122018 in words is "twenty-one billion, two hundred twenty-one million, one hundred twenty-two thousand, eighteen".