121542012541 has 4 divisors (see below), whose sum is σ = 121564851232. Its totient is φ = 121519173852.

The previous prime is 121542012539. The next prime is 121542012617. The reversal of 121542012541 is 145210245121.

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: 145210245121 = 113 ⋅1285046417.

It is a cyclic number.

It is not a de Polignac number, because 121542012541 - 2¹ = 121542012539 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121542012341) 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, 11411361 + ... + 11422006.

It is an arithmetic number, because the mean of its divisors is an integer number (30391212808).

Almost surely, 2^121542012541 is an apocalyptic number.

It is an amenable number.

121542012541 is a deficient number, since it is larger than the sum of its proper divisors (22838691).

121542012541 is an equidigital number, since it uses as much as digits as its factorization.

121542012541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22838690.

The product of its (nonzero) digits is 3200, while the sum is 28.

Adding to 121542012541 its reverse (145210245121), we get a palindrome (266752257662).

The spelling of 121542012541 in words is "one hundred twenty-one billion, five hundred forty-two million, twelve thousand, five hundred forty-one".