11915959121 has 6 divisors (see below), whose sum is σ = 13097707266. Its totient is φ = 10832690000.

The previous prime is 11915959063. The next prime is 11915959129. The reversal of 11915959121 is 12195951911.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 6281355025 + 5634604096 = 79255^2 + 75064^2 .

It is not a de Polignac number, because 11915959121 - 2⁶ = 11915959057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11915959129) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 49239380 + ... + 49239621.

It is an arithmetic number, because the mean of its divisors is an integer number (2182951211).

Almost surely, 2^11915959121 is an apocalyptic number.

11915959121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11915959121 is a deficient number, since it is larger than the sum of its proper divisors (1181748145).

11915959121 is an equidigital number, since it uses as much as digits as its factorization.

11915959121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98479023 (or 98479012 counting only the distinct ones).

The product of its digits is 36450, while the sum is 44.

The spelling of 11915959121 in words is "eleven billion, nine hundred fifteen million, nine hundred fifty-nine thousand, one hundred twenty-one".