221680536 has 128 divisors (see below), whose sum is σ = 696729600. Its totient is φ = 57098880.

The previous prime is 221680519. The next prime is 221680549. The reversal of 221680536 is 635086122.

221680536 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 221680497 and 221680506.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 256441 + ... + 257303.

It is an arithmetic number, because the mean of its divisors is an integer number (5443200).

Almost surely, 2^221680536 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 221680536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (348364800).

221680536 is an abundant number, since it is smaller than the sum of its proper divisors (475049064).

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

221680536 is a wasteful number, since it uses less digits than its factorization.

221680536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1029 (or 1025 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 33.

The square root of 221680536 is about 14888.9400562968. The cubic root of 221680536 is about 605.2143092503.

The spelling of 221680536 in words is "two hundred twenty-one million, six hundred eighty thousand, five hundred thirty-six".