221451340 has 48 divisors (see below), whose sum is σ = 514311840. Its totient is φ = 79418880.

The previous prime is 221451301. The next prime is 221451341. The reversal of 221451340 is 43154122.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (221451341) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9166 + ... + 22954.

It is an arithmetic number, because the mean of its divisors is an integer number (10714830).

Almost surely, 2^221451340 is an apocalyptic number.

221451340 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 221451340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (257155920).

221451340 is an abundant number, since it is smaller than the sum of its proper divisors (292860500).

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

221451340 is a wasteful number, since it uses less digits than its factorization.

221451340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13882 (or 13880 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 221451340 is about 14881.2412116732. The cubic root of 221451340 is about 605.0056598519.

The spelling of 221451340 in words is "two hundred twenty-one million, four hundred fifty-one thousand, three hundred forty".