221347440 has 240 divisors, whose sum is σ = 787378176. Its totient is φ = 55641600.

The previous prime is 221347433. The next prime is 221347447. The reversal of 221347440 is 44743122.

221347440 is a `hidden beast` number, since 2 + 213 + 4 + 7 + 440 = 666.

It is an interprime number because it is at equal distance from previous prime (221347433) and next prime (221347447).

It is a tau number, because it is divible by the number of its divisors (240).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221347447) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1048935 + ... + 1049145.

Almost surely, 2^221347440 is an apocalyptic number.

221347440 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 221347440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (393689088).

221347440 is an abundant number, since it is smaller than the sum of its proper divisors (566030736).

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

221347440 is a wasteful number, since it uses less digits than its factorization.

221347440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308 (or 299 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 27.

The square root of 221347440 is about 14877.7498298634. The cubic root of 221347440 is about 604.9110266901.

The spelling of 221347440 in words is "two hundred twenty-one million, three hundred forty-seven thousand, four hundred forty".