121211666651 has 8 divisors (see below), whose sum is σ = 124149434640. Its totient is φ = 118307094048.

The previous prime is 121211666623. The next prime is 121211666669. The reversal of 121211666651 is 156666112121.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121211666651 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121211666351) 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, 8291456 + ... + 8306061.

It is an arithmetic number, because the mean of its divisors is an integer number (15518679330).

Almost surely, 2^121211666651 is an apocalyptic number.

121211666651 is a deficient number, since it is larger than the sum of its proper divisors (2937767989).

121211666651 is a wasteful number, since it uses less digits than its factorization.

121211666651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16597693.

The product of its digits is 25920, while the sum is 38.

Adding to 121211666651 its reverse (156666112121), we get a palindrome (277877778772).

The spelling of 121211666651 in words is "one hundred twenty-one billion, two hundred eleven million, six hundred sixty-six thousand, six hundred fifty-one".