211222561 has 12 divisors (see below), whose sum is σ = 239663872. Its totient is φ = 185823000.

The previous prime is 211222553. The next prime is 211222643. The reversal of 211222561 is 165222112.

It is not a de Polignac number, because 211222561 - 2³ = 211222553 is a prime.

It is a super-2 number, since 2×211222561² = 89229940550797442, which contains 22 as substring.

It is a hoax number, since the sum of its digits (22) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (211222511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24405 + ... + 31906.

Almost surely, 2^211222561 is an apocalyptic number.

It is an amenable number.

211222561 is a deficient number, since it is larger than the sum of its proper divisors (28441311).

211222561 is a wasteful number, since it uses less digits than its factorization.

211222561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56364 (or 56353 counting only the distinct ones).

The product of its digits is 480, while the sum is 22.

The square root of 211222561 is about 14533.4978927992. The cubic root of 211222561 is about 595.5434255667.

Adding to 211222561 its reverse (165222112), we get a palindrome (376444673).

The spelling of 211222561 in words is "two hundred eleven million, two hundred twenty-two thousand, five hundred sixty-one".