221764080 has 160 divisors (see below), whose sum is σ = 727953408. Its totient is φ = 55756800.

The previous prime is 221764079. The next prime is 221764087. The reversal of 221764080 is 80467122.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221764087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 304677 + ... + 305403.

Almost surely, 2^221764080 is an apocalyptic number.

221764080 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 221764080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (363976704).

221764080 is an abundant number, since it is smaller than the sum of its proper divisors (506189328).

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

221764080 is a wasteful number, since it uses less digits than its factorization.

221764080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 815 (or 809 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 221764080 is about 14891.7453644628. The cubic root of 221764080 is about 605.2903280636.

The spelling of 221764080 in words is "two hundred twenty-one million, seven hundred sixty-four thousand, eighty".