221610612 has 48 divisors (see below), whose sum is σ = 554182272. Its totient is φ = 68745600.

The previous prime is 221610601. The next prime is 221610629. The reversal of 221610612 is 216016122.

It is a super-2 number, since 2×221610612² = 98222526702029088, which contains 22 as substring.

It is a congruent number.

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, 639 + ... + 21062.

It is an arithmetic number, because the mean of its divisors is an integer number (11545464).

Almost surely, 2^221610612 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221610612, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (277091136).

221610612 is an abundant number, since it is smaller than the sum of its proper divisors (332571660).

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

221610612 is a wasteful number, since it uses less digits than its factorization.

221610612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21768 (or 21766 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 221610612 is about 14886.5916851373. The cubic root of 221610612 is about 605.1506689379.

Adding to 221610612 its reverse (216016122), we get a palindrome (437626734).

It can be divided in two parts, 221610 and 612, that added together give a palindrome (222222).

The spelling of 221610612 in words is "two hundred twenty-one million, six hundred ten thousand, six hundred twelve".