221376788 has 24 divisors (see below), whose sum is σ = 411301800. Its totient is φ = 103897088.

The previous prime is 221376787. The next prime is 221376811. The reversal of 221376788 is 887673122.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 54140164 + 167236624 = 7358^2 + 12932^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221376787) 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, 22268 + ... + 30636.

It is an arithmetic number, because the mean of its divisors is an integer number (17137575).

Almost surely, 2^221376788 is an apocalyptic number.

It is an amenable number.

221376788 is a deficient number, since it is larger than the sum of its proper divisors (189925012).

221376788 is a wasteful number, since it uses less digits than its factorization.

221376788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8779 (or 8777 counting only the distinct ones).

The product of its digits is 225792, while the sum is 44.

The square root of 221376788 is about 14878.7361022366. The cubic root of 221376788 is about 604.9377601432.

The spelling of 221376788 in words is "two hundred twenty-one million, three hundred seventy-six thousand, seven hundred eighty-eight".