221431040 has 36 divisors (see below), whose sum is σ = 530399604. Its totient is φ = 88571904.

The previous prime is 221431039. The next prime is 221431057. The reversal of 221431040 is 40134122.

It can be written as a sum of positive squares in 2 ways, for example, as 150601984 + 70829056 = 12272^2 + 8416^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85217 + ... + 87776.

Almost surely, 2^221431040 is an apocalyptic number.

221431040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221431040 is an abundant number, since it is smaller than the sum of its proper divisors (308968564).

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

221431040 is an equidigital number, since it uses as much as digits as its factorization.

221431040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173014 (or 173000 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 221431040 is about 14880.5591292801. The cubic root of 221431040 is about 604.9871727353.

Adding to 221431040 its reverse (40134122), we get a palindrome (261565162).

The spelling of 221431040 in words is "two hundred twenty-one million, four hundred thirty-one thousand, forty".