221660472 has 64 divisors (see below), whose sum is σ = 606418560. Its totient is φ = 66960000.

The previous prime is 221660471. The next prime is 221660489. The reversal of 221660472 is 274066122.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221660471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 97347 + ... + 99597.

It is an arithmetic number, because the mean of its divisors is an integer number (9475290).

Almost surely, 2^221660472 is an apocalyptic number.

221660472 is a gapful number since it is divisible by the number (22) 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 221660472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (303209280).

221660472 is an abundant number, since it is smaller than the sum of its proper divisors (384758088).

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

221660472 is a wasteful number, since it uses less digits than its factorization.

221660472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2644 (or 2640 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 30.

The square root of 221660472 is about 14888.2662523210. The cubic root of 221660472 is about 605.1960496615.

The spelling of 221660472 in words is "two hundred twenty-one million, six hundred sixty thousand, four hundred seventy-two".