221281152 has 64 divisors (see below), whose sum is σ = 597801600. Its totient is φ = 72502784.

The previous prime is 221281147. The next prime is 221281157. The reversal of 221281152 is 251182122.

It is an interprime number because it is at equal distance from previous prime (221281147) and next prime (221281157).

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221281157) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17773 + ... + 27539.

It is an arithmetic number, because the mean of its divisors is an integer number (9340650).

Almost surely, 2^221281152 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221281152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (298900800).

221281152 is an abundant number, since it is smaller than the sum of its proper divisors (376520448).

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

221281152 is an equidigital number, since it uses as much as digits as its factorization.

221281152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9843 (or 9831 counting only the distinct ones).

The product of its digits is 640, while the sum is 24.

The square root of 221281152 is about 14875.5219068105. The cubic root of 221281152 is about 604.8506354403.

The spelling of 221281152 in words is "two hundred twenty-one million, two hundred eighty-one thousand, one hundred fifty-two".