13218221856 has 96 divisors (see below), whose sum is σ = 40156784640. Its totient is φ = 3728814336.

The previous prime is 13218221851. The next prime is 13218221879. The reversal of 13218221856 is 65812281231.

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (13218221851) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 71406 + ... + 177581.

It is an arithmetic number, because the mean of its divisors is an integer number (418299840).

Almost surely, 2^13218221856 is an apocalyptic number.

13218221856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

13218221856 is an abundant number, since it is smaller than the sum of its proper divisors (26938562784).

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

13218221856 is a wasteful number, since it uses less digits than its factorization.

13218221856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249086 (or 249078 counting only the distinct ones).

The product of its digits is 46080, while the sum is 39.

The spelling of 13218221856 in words is "thirteen billion, two hundred eighteen million, two hundred twenty-one thousand, eight hundred fifty-six".