221402836 has 12 divisors (see below), whose sum is σ = 394765812. Its totient is φ = 108612608.

The previous prime is 221402827. The next prime is 221402873. The reversal of 221402836 is 638204122.

221402836 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 86378436 + 135024400 = 9294^2 + 11620^2 .

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, 521965 + ... + 522388.

It is an arithmetic number, because the mean of its divisors is an integer number (32897151).

Almost surely, 2^221402836 is an apocalyptic number.

It is an amenable number.

221402836 is a deficient number, since it is larger than the sum of its proper divisors (173362976).

221402836 is a wasteful number, since it uses less digits than its factorization.

221402836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1044410 (or 1044408 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 221402836 is about 14879.6114196574. The cubic root of 221402836 is about 604.9614856069.

Adding to 221402836 its reverse (638204122), we get a palindrome (859606958).

It can be divided in two parts, 22140 and 2836, that added together give a triangular number (24976 = T₂₂₃).

The spelling of 221402836 in words is "two hundred twenty-one million, four hundred two thousand, eight hundred thirty-six".