221297661544960 has 1920 divisors, whose sum is σ = 746521119590400. Its totient is φ = 62448070164480.

The previous prime is 221297661544937. The next prime is 221297661545003. The reversal of 221297661544960 is 69445166792122.

It is a Harshad number since it is a multiple of its sum of digits (64).

It is a junction number, because it is equal to n+sod(n) for n = 221297661544892 and 221297661544901.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 73204650009 + ... + 73204653031.

It is an arithmetic number, because the mean of its divisors is an integer number (388813083120).

Almost surely, 2^{221297661544960} is an apocalyptic number.

221297661544960 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221297661544960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (373260559795200).

221297661544960 is an abundant number, since it is smaller than the sum of its proper divisors (525223458045440).

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

221297661544960 is a wasteful number, since it uses less digits than its factorization.

221297661544960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3155 (or 3114 counting only the distinct ones).

The product of its (nonzero) digits is 78382080, while the sum is 64.

The spelling of 221297661544960 in words is "two hundred twenty-one trillion, two hundred ninety-seven billion, six hundred sixty-one million, five hundred forty-four thousand, nine hundred sixty".