121115531 has 4 divisors (see below), whose sum is σ = 128239992. Its totient is φ = 113991072.

The previous prime is 121115503. The next prime is 121115549. The reversal of 121115531 is 135511121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 135511121 = 2423 ⋅55927.

It is a cyclic number.

It is not a de Polignac number, because 121115531 - 2²² = 116921227 is a prime.

It is a super-2 number, since 2×121115531² = 29337943698823922, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 5.

It is not an unprimeable number, because it can be changed into a prime (121115131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3562205 + ... + 3562238.

It is an arithmetic number, because the mean of its divisors is an integer number (32059998).

Almost surely, 2^121115531 is an apocalyptic number.

121115531 is a deficient number, since it is larger than the sum of its proper divisors (7124461).

121115531 is an equidigital number, since it uses as much as digits as its factorization.

121115531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7124460.

The product of its digits is 150, while the sum is 20.

The square root of 121115531 is about 11005.2501561755. The cubic root of 121115531 is about 494.7661119994.

Adding to 121115531 its reverse (135511121), we get a palindrome (256626652).

The spelling of 121115531 in words is "one hundred twenty-one million, one hundred fifteen thousand, five hundred thirty-one".