212166656 has 72 divisors (see below), whose sum is σ = 460122390. Its totient is φ = 97763328.

The previous prime is 212166649. The next prime is 212166667. The reversal of 212166656 is 656661212.

It can be written as a sum of positive squares in 3 ways, for example, as 35808256 + 176358400 = 5984^2 + 13280^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 345806 + ... + 346418.

Almost surely, 2^212166656 is an apocalyptic number.

212166656 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 212166656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (230061195).

212166656 is an abundant number, since it is smaller than the sum of its proper divisors (247955734).

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

212166656 is an equidigital number, since it uses as much as digits as its factorization.

212166656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 661 (or 628 counting only the distinct ones).

The product of its digits is 25920, while the sum is 35.

The square root of 212166656 is about 14565.9416448096. The cubic root of 212166656 is about 596.4294009280.

It can be divided in two parts, 21216 and 6656, that added together give a palindrome (27872).

The spelling of 212166656 in words is "two hundred twelve million, one hundred sixty-six thousand, six hundred fifty-six".