221401240 has 16 divisors (see below), whose sum is σ = 498152880. Its totient is φ = 88560480.

The previous prime is 221401199. The next prime is 221401261. The reversal of 221401240 is 42104122.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2767476 + ... + 2767555.

It is an arithmetic number, because the mean of its divisors is an integer number (31134555).

Almost surely, 2^221401240 is an apocalyptic number.

221401240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221401240 is an abundant number, since it is smaller than the sum of its proper divisors (276751640).

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

221401240 is a wasteful number, since it uses less digits than its factorization.

221401240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5535042 (or 5535038 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 221401240 is about 14879.5577891280. The cubic root of 221401240 is about 604.9600319657.

Adding to 221401240 its reverse (42104122), we get a palindrome (263505362).

The spelling of 221401240 in words is "two hundred twenty-one million, four hundred one thousand, two hundred forty".