121531112413 has 4 divisors (see below), whose sum is σ = 122896630620. Its totient is φ = 120165594208.

The previous prime is 121531112399. The next prime is 121531112429. The reversal of 121531112413 is 314211135121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 314211135121 = 13 ⋅24170087317.

It can be written as a sum of positive squares in 2 ways, for example, as 16125698169 + 105405414244 = 126987^2 + 324662^2 .

It is a cyclic number.

It is not a de Polignac number, because 121531112413 - 2³³ = 112941177821 is a prime.

It is a super-2 number, since 2×121531112413² (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 (121531115413) 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, 682758970 + ... + 682759147.

It is an arithmetic number, because the mean of its divisors is an integer number (30724157655).

Almost surely, 2^121531112413 is an apocalyptic number.

It is an amenable number.

121531112413 is a deficient number, since it is larger than the sum of its proper divisors (1365518207).

121531112413 is an equidigital number, since it uses as much as digits as its factorization.

121531112413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1365518206.

The product of its digits is 720, while the sum is 25.

Adding to 121531112413 its reverse (314211135121), we get a palindrome (435742247534).

The spelling of 121531112413 in words is "one hundred twenty-one billion, five hundred thirty-one million, one hundred twelve thousand, four hundred thirteen".