212060121661 has 4 divisors (see below), whose sum is σ = 212067629824. Its totient is φ = 212052613500.

The previous prime is 212060121653. The next prime is 212060121671. The reversal of 212060121661 is 166121060212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 212060121661 - 2³ = 212060121653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212060121641) 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, 3711555 + ... + 3768256.

It is an arithmetic number, because the mean of its divisors is an integer number (53016907456).

Almost surely, 2^212060121661 is an apocalyptic number.

It is an amenable number.

212060121661 is a deficient number, since it is larger than the sum of its proper divisors (7508163).

212060121661 is an equidigital number, since it uses as much as digits as its factorization.

212060121661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7508162.

The product of its (nonzero) digits is 1728, while the sum is 28.

Adding to 212060121661 its reverse (166121060212), we get a palindrome (378181181873).

The spelling of 212060121661 in words is "two hundred twelve billion, sixty million, one hundred twenty-one thousand, six hundred sixty-one".