212111656 has 8 divisors (see below), whose sum is σ = 397709370. Its totient is φ = 106055824.

The previous prime is 212111651. The next prime is 212111659. The reversal of 212111656 is 656111212.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 170302500 + 41809156 = 13050^2 + 6466^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×212111656² = 89982709222124672, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 212111656.

It is not an unprimeable number, because it can be changed into a prime (212111651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13256971 + ... + 13256986.

Almost surely, 2^212111656 is an apocalyptic number.

It is an amenable number.

212111656 is a deficient number, since it is larger than the sum of its proper divisors (185597714).

212111656 is a wasteful number, since it uses less digits than its factorization.

212111656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26513963 (or 26513959 counting only the distinct ones).

The product of its digits is 720, while the sum is 25.

The square root of 212111656 is about 14564.0535566167. The cubic root of 212111656 is about 596.3778589741.

Adding to 212111656 its reverse (656111212), we get a palindrome (868222868).

The spelling of 212111656 in words is "two hundred twelve million, one hundred eleven thousand, six hundred fifty-six".