221788940 has 24 divisors (see below), whose sum is σ = 466074672. Its totient is φ = 88655040.

The previous prime is 221788939. The next prime is 221788943. The reversal of 221788940 is 49887122.

It is not an unprimeable number, because it can be changed into a prime (221788943) 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 7 ways as a sum of consecutive naturals, for example, 36950 + ... + 42530.

It is an arithmetic number, because the mean of its divisors is an integer number (19419778).

Almost surely, 2^221788940 is an apocalyptic number.

221788940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221788940 is an abundant number, since it is smaller than the sum of its proper divisors (244285732).

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

221788940 is a wasteful number, since it uses less digits than its factorization.

221788940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7577 (or 7575 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 41.

The square root of 221788940 is about 14892.5800316802. The cubic root of 221788940 is about 605.3129451248.

The spelling of 221788940 in words is "two hundred twenty-one million, seven hundred eighty-eight thousand, nine hundred forty".