121761231523 has 4 divisors (see below), whose sum is σ = 121963829848. Its totient is φ = 121558633200.

The previous prime is 121761231509. The next prime is 121761231539. The reversal of 121761231523 is 325132167121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 325132167121 = 139 ⋅2339080339.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121761231523 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121761231563) 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, 101298261 + ... + 101299462.

It is an arithmetic number, because the mean of its divisors is an integer number (30490957462).

Almost surely, 2^121761231523 is an apocalyptic number.

121761231523 is a deficient number, since it is larger than the sum of its proper divisors (202598325).

121761231523 is an equidigital number, since it uses as much as digits as its factorization.

121761231523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202598324.

The product of its digits is 15120, while the sum is 34.

Adding to 121761231523 its reverse (325132167121), we get a palindrome (446893398644).

The spelling of 121761231523 in words is "one hundred twenty-one billion, seven hundred sixty-one million, two hundred thirty-one thousand, five hundred twenty-three".