212005561 has 8 divisors (see below), whose sum is σ = 215754048. Its totient is φ = 208266000.

The previous prime is 212005529. The next prime is 212005583. The reversal of 212005561 is 165500212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 212005561 - 2⁵ = 212005529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (212005961) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61206 + ... + 64576.

It is an arithmetic number, because the mean of its divisors is an integer number (26969256).

Almost surely, 2^212005561 is an apocalyptic number.

It is an amenable number.

212005561 is a deficient number, since it is larger than the sum of its proper divisors (3748487).

212005561 is a wasteful number, since it uses less digits than its factorization.

212005561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4463.

The product of its (nonzero) digits is 600, while the sum is 22.

The square root of 212005561 is about 14560.4107428328. The cubic root of 212005561 is about 596.2784093691.

Adding to 212005561 its reverse (165500212), we get a palindrome (377505773).

The spelling of 212005561 in words is "two hundred twelve million, five thousand, five hundred sixty-one".