221216404640 has 96 divisors (see below), whose sum is σ = 651582900864. Its totient is φ = 68950563840.

The previous prime is 221216404573. The next prime is 221216404697. The reversal of 221216404640 is 46404612122.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 221216404597 and 221216404606.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8965619 + ... + 8990258.

It is an arithmetic number, because the mean of its divisors is an integer number (6787321884).

Almost surely, 2^221216404640 is an apocalyptic number.

221216404640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221216404640 is an abundant number, since it is smaller than the sum of its proper divisors (430366496224).

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

221216404640 is a wasteful number, since it uses less digits than its factorization.

221216404640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17955910 (or 17955902 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 32.

The spelling of 221216404640 in words is "two hundred twenty-one billion, two hundred sixteen million, four hundred four thousand, six hundred forty".