121399278331 has 4 divisors (see below), whose sum is σ = 121400078464. Its totient is φ = 121398478200.

The previous prime is 121399278241. The next prime is 121399278347. The reversal of 121399278331 is 133872993121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 133872993121 = 7 ⋅19124713303.

It is a cyclic number.

It is not a de Polignac number, because 121399278331 - 2⁹ = 121399277819 is a prime.

It is a super-2 number, since 2×121399278331² (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 (121399278031) 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, 94875 + ... + 501796.

It is an arithmetic number, because the mean of its divisors is an integer number (30350019616).

Almost surely, 2^121399278331 is an apocalyptic number.

121399278331 is a deficient number, since it is larger than the sum of its proper divisors (800133).

121399278331 is an equidigital number, since it uses as much as digits as its factorization.

121399278331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 800132.

The product of its digits is 489888, while the sum is 49.

The spelling of 121399278331 in words is "one hundred twenty-one billion, three hundred ninety-nine million, two hundred seventy-eight thousand, three hundred thirty-one".