221534440 has 16 divisors (see below), whose sum is σ = 498452580. Its totient is φ = 88613760.

The previous prime is 221534437. The next prime is 221534449. The reversal of 221534440 is 44435122.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 221473924 + 60516 = 14882^2 + 246^2 .

It is a super-2 number, since 2×221534440² = 98155016212227200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221534449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2769141 + ... + 2769220.

Almost surely, 2^221534440 is an apocalyptic number.

221534440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221534440 is an abundant number, since it is smaller than the sum of its proper divisors (276918140).

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

221534440 is a wasteful number, since it uses less digits than its factorization.

221534440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5538372 (or 5538368 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 25.

The square root of 221534440 is about 14884.0330555935. The cubic root of 221534440 is about 605.0813268629.

Adding to 221534440 its reverse (44435122), we get a palindrome (265969562).

The spelling of 221534440 in words is "two hundred twenty-one million, five hundred thirty-four thousand, four hundred forty".