121397991481 has 8 divisors (see below), whose sum is σ = 130741007040. Its totient is φ = 112055648592.

The previous prime is 121397991439. The next prime is 121397991497. The reversal of 121397991481 is 184199793121.

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 121397991481 - 2¹⁵ = 121397958713 is a prime.

It is a super-2 number, since 2×121397991481² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121397991401) 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 7 ways as a sum of consecutive naturals, for example, 244116 + ... + 549898.

It is an arithmetic number, because the mean of its divisors is an integer number (16342625880).

Almost surely, 2^121397991481 is an apocalyptic number.

It is an amenable number.

121397991481 is a deficient number, since it is larger than the sum of its proper divisors (9343015559).

121397991481 is a wasteful number, since it uses less digits than its factorization.

121397991481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 336335.

The product of its digits is 979776, while the sum is 55.

The spelling of 121397991481 in words is "one hundred twenty-one billion, three hundred ninety-seven million, nine hundred ninety-one thousand, four hundred eighty-one".