221015680 has 64 divisors (see below), whose sum is σ = 532097280. Its totient is φ = 87782400.

The previous prime is 221015677. The next prime is 221015681. The reversal of 221015680 is 86510122.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221015681) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 95497 + ... + 97783.

It is an arithmetic number, because the mean of its divisors is an integer number (8314020).

Almost surely, 2^221015680 is an apocalyptic number.

221015680 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 221015680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (266048640).

221015680 is an abundant number, since it is smaller than the sum of its proper divisors (311081600).

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

221015680 is a wasteful number, since it uses less digits than its factorization.

221015680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2457 (or 2445 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 221015680 is about 14866.5961134350. The cubic root of 221015680 is about 604.6086579653.

The spelling of 221015680 in words is "two hundred twenty-one million, fifteen thousand, six hundred eighty".