221610870 has 128 divisors (see below), whose sum is σ = 670118400. Its totient is φ = 51663744.

The previous prime is 221610859. The next prime is 221610877. The reversal of 221610870 is 78016122.

It is a super-2 number, since 2×221610870² = 98222755404313800, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221610877) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 65029 + ... + 68351.

It is an arithmetic number, because the mean of its divisors is an integer number (5235300).

Almost surely, 2^221610870 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221610870, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (335059200).

221610870 is an abundant number, since it is smaller than the sum of its proper divisors (448507530).

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

221610870 is a wasteful number, since it uses less digits than its factorization.

221610870 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3371 (or 3365 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 221610870 is about 14886.6003506509. The cubic root of 221610870 is about 605.1509037775.

Adding to 221610870 its reverse (78016122), we get a palindrome (299626992).

The spelling of 221610870 in words is "two hundred twenty-one million, six hundred ten thousand, eight hundred seventy".