221613138 has 32 divisors (see below), whose sum is σ = 492960000. Its totient is φ = 73798128.

The previous prime is 221613113. The next prime is 221613143. The reversal of 221613138 is 831316122.

It is a happy number.

It is a super-2 number, since 2×221613138² = 98224765868414088, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 106920 + ... + 108972.

It is an arithmetic number, because the mean of its divisors is an integer number (15405000).

Almost surely, 2^221613138 is an apocalyptic number.

221613138 is an abundant number, since it is smaller than the sum of its proper divisors (271346862).

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

221613138 is a wasteful number, since it uses less digits than its factorization.

221613138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4063 (or 4057 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 221613138 is about 14886.6765263440. The cubic root of 221613138 is about 605.1529681732.

The spelling of 221613138 in words is "two hundred twenty-one million, six hundred thirteen thousand, one hundred thirty-eight".