121658321281 has 16 divisors (see below), whose sum is σ = 140940979200. Its totient is φ = 102855455568.

The previous prime is 121658321233. The next prime is 121658321303. The reversal of 121658321281 is 182123856121.

It is a cyclic number.

It is not a de Polignac number, because 121658321281 - 2⁷ = 121658321153 is a prime.

It is a super-2 number, since 2×121658321281² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (121658321231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 190500 + ... + 528778.

It is an arithmetic number, because the mean of its divisors is an integer number (8808811200).

Almost surely, 2^121658321281 is an apocalyptic number.

It is an amenable number.

121658321281 is a deficient number, since it is larger than the sum of its proper divisors (19282657919).

121658321281 is an equidigital number, since it uses as much as digits as its factorization.

121658321281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 338988.

The product of its digits is 46080, while the sum is 40.

The spelling of 121658321281 in words is "one hundred twenty-one billion, six hundred fifty-eight million, three hundred twenty-one thousand, two hundred eighty-one".