121209446981 has 4 divisors (see below), whose sum is σ = 138525082272. Its totient is φ = 103893811692.

The previous prime is 121209446947. The next prime is 121209447031. The reversal of 121209446981 is 189644902121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 189644902121 = 23 ⋅8245430527.

It is a cyclic number.

It is not a de Polignac number, because 121209446981 - 2¹⁰ = 121209445957 is a prime.

It is a super-2 number, since 2×121209446981² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121209446081) 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, 8657817635 + ... + 8657817648.

It is an arithmetic number, because the mean of its divisors is an integer number (34631270568).

Almost surely, 2^121209446981 is an apocalyptic number.

It is an amenable number.

121209446981 is a deficient number, since it is larger than the sum of its proper divisors (17315635291).

121209446981 is an equidigital number, since it uses as much as digits as its factorization.

121209446981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17315635290.

The product of its (nonzero) digits is 248832, while the sum is 47.

The spelling of 121209446981 in words is "one hundred twenty-one billion, two hundred nine million, four hundred forty-six thousand, nine hundred eighty-one".