121652221661 has 8 divisors (see below), whose sum is σ = 124488814680. Its totient is φ = 118835675712.

The previous prime is 121652221631. The next prime is 121652221681. The reversal of 121652221661 is 166122256121.

It can be written as a sum of positive squares in 4 ways, for example, as 35562793561 + 86089428100 = 188581^2 + 293410^2 .

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 121652221661 - 2²² = 121648027357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121652221631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4999490 + ... + 5023763.

It is an arithmetic number, because the mean of its divisors is an integer number (15561101835).

Almost surely, 2^121652221661 is an apocalyptic number.

It is an amenable number.

121652221661 is a deficient number, since it is larger than the sum of its proper divisors (2836593019).

121652221661 is a wasteful number, since it uses less digits than its factorization.

121652221661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10023535.

The product of its digits is 17280, while the sum is 35.

Adding to 121652221661 its reverse (166122256121), we get a palindrome (287774477782).

The spelling of 121652221661 in words is "one hundred twenty-one billion, six hundred fifty-two million, two hundred twenty-one thousand, six hundred sixty-one".