221456620 has 144 divisors (see below), whose sum is σ = 619375680. Its totient is φ = 64880640.

The previous prime is 221456611. The next prime is 221456629. The reversal of 221456620 is 26654122.

221456620 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (221456611) and next prime (221456629).

It is a Harshad number since it is a multiple of its sum of digits (28).

It is not an unprimeable number, because it can be changed into a prime (221456629) 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, 287596 + ... + 288364.

It is an arithmetic number, because the mean of its divisors is an integer number (4301220).

Almost surely, 2^221456620 is an apocalyptic number.

221456620 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 221456620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (309687840).

221456620 is an abundant number, since it is smaller than the sum of its proper divisors (397919060).

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

221456620 is a wasteful number, since it uses less digits than its factorization.

221456620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 824 (or 811 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 221456620 is about 14881.4186151724. The cubic root of 221456620 is about 605.0104681384.

The spelling of 221456620 in words is "two hundred twenty-one million, four hundred fifty-six thousand, six hundred twenty".