221613388 has 6 divisors (see below), whose sum is σ = 387823436. Its totient is φ = 110806692.

The previous prime is 221613383. The next prime is 221613391. The reversal of 221613388 is 883316122.

It is a happy number.

221613388 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×221613388² = 98224987481677088, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221613383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27701670 + ... + 27701677.

Almost surely, 2^221613388 is an apocalyptic number.

It is an amenable number.

221613388 is a deficient number, since it is larger than the sum of its proper divisors (166210048).

221613388 is a wasteful number, since it uses less digits than its factorization.

221613388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55403351 (or 55403349 counting only the distinct ones).

The product of its digits is 13824, while the sum is 34.

The square root of 221613388 is about 14886.6849231117. The cubic root of 221613388 is about 605.1531957292.

The spelling of 221613388 in words is "two hundred twenty-one million, six hundred thirteen thousand, three hundred eighty-eight".