221212013240 has 16 divisors (see below), whose sum is σ = 497727029880. Its totient is φ = 88484805280.

The previous prime is 221212013233. The next prime is 221212013249. The reversal of 221212013240 is 42310212122.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221212013249) 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, 2765150126 + ... + 2765150205.

Almost surely, 2^221212013240 is an apocalyptic number.

221212013240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221212013240 is an abundant number, since it is smaller than the sum of its proper divisors (276515016640).

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

221212013240 is a wasteful number, since it uses less digits than its factorization.

221212013240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5530300342 (or 5530300338 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 221212013240 its reverse (42310212122), we get a palindrome (263522225362).

The spelling of 221212013240 in words is "two hundred twenty-one billion, two hundred twelve million, thirteen thousand, two hundred forty".