221464540 has 48 divisors (see below), whose sum is σ = 509582304. Its totient is φ = 80179200.

The previous prime is 221464469. The next prime is 221464543. The reversal of 221464540 is 45464122.

It is a junction number, because it is equal to n+sod(n) for n = 221464499 and 221464508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221464543) 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, 50932 + ... + 55108.

It is an arithmetic number, because the mean of its divisors is an integer number (10616298).

Almost surely, 2^221464540 is an apocalyptic number.

221464540 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 221464540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (254791152).

221464540 is an abundant number, since it is smaller than the sum of its proper divisors (288117764).

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

221464540 is a wasteful number, since it uses less digits than its factorization.

221464540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4438 (or 4436 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 28.

The square root of 221464540 is about 14881.6847164560. The cubic root of 221464540 is about 605.0176804250.

The spelling of 221464540 in words is "two hundred twenty-one million, four hundred sixty-four thousand, five hundred forty".