221461903656 has 320 divisors, whose sum is σ = 738545280000. Its totient is φ = 60667729920.

The previous prime is 221461903627. The next prime is 221461903657. The reversal of 221461903656 is 656309164122.

221461903656 is a `hidden beast` number, since 2 + 21 + 4 + 619 + 0 + 3 + 6 + 5 + 6 = 666.

It is not an unprimeable number, because it can be changed into a prime (221461903657) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 15319920 + ... + 15334368.

It is an arithmetic number, because the mean of its divisors is an integer number (2307954000).

Almost surely, 2^221461903656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221461903656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (369272640000).

221461903656 is an abundant number, since it is smaller than the sum of its proper divisors (517083376344).

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

221461903656 is a wasteful number, since it uses less digits than its factorization.

221461903656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14614 (or 14601 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The spelling of 221461903656 in words is "two hundred twenty-one billion, four hundred sixty-one million, nine hundred three thousand, six hundred fifty-six".