121542431 has 4 divisors (see below), whose sum is σ = 121824864. Its totient is φ = 121260000.

The previous prime is 121542397. The next prime is 121542457. The reversal of 121542431 is 134245121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121542431 is a prime.

It is a super-2 number, since 2×121542431² = 29545125066779522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121542397 and 121542406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121542731) 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, 140570 + ... + 141431.

It is an arithmetic number, because the mean of its divisors is an integer number (30456216).

Almost surely, 2^121542431 is an apocalyptic number.

121542431 is a deficient number, since it is larger than the sum of its proper divisors (282433).

121542431 is an equidigital number, since it uses as much as digits as its factorization.

121542431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 282432.

The product of its digits is 960, while the sum is 23.

The square root of 121542431 is about 11024.6283837597. The cubic root of 121542431 is about 495.3467366218.

Adding to 121542431 its reverse (134245121), we get a palindrome (255787552).

The spelling of 121542431 in words is "one hundred twenty-one million, five hundred forty-two thousand, four hundred thirty-one".