221400240 has 80 divisors (see below), whose sum is σ = 695797728. Its totient is φ = 58226688.

The previous prime is 221400229. The next prime is 221400241. The reversal of 221400240 is 42004122.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is not an unprimeable number, because it can be changed into a prime (221400241) 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, 11202 + ... + 23838.

Almost surely, 2^221400240 is an apocalyptic number.

221400240 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 221400240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (347898864).

221400240 is an abundant number, since it is smaller than the sum of its proper divisors (474397488).

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

221400240 is a wasteful number, since it uses less digits than its factorization.

221400240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12726 (or 12720 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 15.

The square root of 221400240 is about 14879.5241859409. The cubic root of 221400240 is about 604.9591211594.

Adding to 221400240 its reverse (42004122), we get a palindrome (263404362).

The spelling of 221400240 in words is "two hundred twenty-one million, four hundred thousand, two hundred forty".