221493888 has 288 divisors, whose sum is σ = 804192480. Its totient is φ = 57277440.

The previous prime is 221493869. The next prime is 221493907. The reversal of 221493888 is 888394122.

221493888 is a `hidden beast` number, since 221 + 49 + 388 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (221493869) and next prime (221493907).

It is a tau number, because it is divible by the number of its divisors (288).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

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 35 ways as a sum of consecutive naturals, for example, 975631 + ... + 975857.

It is an arithmetic number, because the mean of its divisors is an integer number (2792335).

Almost surely, 2^221493888 is an apocalyptic number.

221493888 is a gapful number since it is divisible by the number (28) 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 221493888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (402096240).

221493888 is an abundant number, since it is smaller than the sum of its proper divisors (582698592).

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

221493888 is a wasteful number, since it uses less digits than its factorization.

221493888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276 (or 250 counting only the distinct ones).

The product of its digits is 221184, while the sum is 45.

The square root of 221493888 is about 14882.6707280649. The cubic root of 221493888 is about 605.0444044543.

The spelling of 221493888 in words is "two hundred twenty-one million, four hundred ninety-three thousand, eight hundred eighty-eight".