221127788 has 36 divisors (see below), whose sum is σ = 451699920. Its totient is φ = 94443552.

The previous prime is 221127787. The next prime is 221127791. The reversal of 221127788 is 887721122.

It is not an unprimeable number, because it can be changed into a prime (221127787) 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 11 ways as a sum of consecutive naturals, for example, 60353 + ... + 63911.

It is an arithmetic number, because the mean of its divisors is an integer number (12547220).

Almost surely, 2^221127788 is an apocalyptic number.

221127788 is a gapful number since it is divisible by the number (28) 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 221127788, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (225849960).

221127788 is an abundant number, since it is smaller than the sum of its proper divisors (230572132).

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

221127788 is a wasteful number, since it uses less digits than its factorization.

221127788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3894 (or 3885 counting only the distinct ones).

The product of its digits is 25088, while the sum is 38.

The square root of 221127788 is about 14870.3661017475. The cubic root of 221127788 is about 604.7108679234.

The spelling of 221127788 in words is "two hundred twenty-one million, one hundred twenty-seven thousand, seven hundred eighty-eight".