212065561 has 4 divisors (see below), whose sum is σ = 216066852. Its totient is φ = 208064272.

The previous prime is 212065549. The next prime is 212065583. The reversal of 212065561 is 165560212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 138791961 + 73273600 = 11781^2 + 8560^2 .

It is a cyclic number.

It is not a de Polignac number, because 212065561 - 2⁷ = 212065433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (212065501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2000566 + ... + 2000671.

It is an arithmetic number, because the mean of its divisors is an integer number (54016713).

Almost surely, 2^212065561 is an apocalyptic number.

It is an amenable number.

212065561 is a deficient number, since it is larger than the sum of its proper divisors (4001291).

212065561 is an equidigital number, since it uses as much as digits as its factorization.

212065561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4001290.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 212065561 is about 14562.4709785119. The cubic root of 212065561 is about 596.3346552680.

The spelling of 212065561 in words is "two hundred twelve million, sixty-five thousand, five hundred sixty-one".