221090436 has 36 divisors (see below), whose sum is σ = 638706432. Its totient is φ = 63168624.

The previous prime is 221090431. The next prime is 221090437. The reversal of 221090436 is 634090122.

221090436 is a `hidden beast` number, since 221 + 0 + 9 + 0 + 436 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (221090431) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 438420 + ... + 438923.

Almost surely, 2^221090436 is an apocalyptic number.

It is an amenable number.

221090436 is an abundant number, since it is smaller than the sum of its proper divisors (417615996).

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

221090436 is a wasteful number, since it uses less digits than its factorization.

221090436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 877360 (or 877355 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 221090436 is about 14869.1101280473. The cubic root of 221090436 is about 604.6768175786.

The spelling of 221090436 in words is "two hundred twenty-one million, ninety thousand, four hundred thirty-six".