121643542 has 4 divisors (see below), whose sum is σ = 182465316. Its totient is φ = 60821770.

The previous prime is 121643539. The next prime is 121643569. The reversal of 121643542 is 245346121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 245346121 = 31 ⋅7914391.

It is a self number, because there is not a number n which added to its sum of digits gives 121643542.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30410884 + ... + 30410887.

It is an arithmetic number, because the mean of its divisors is an integer number (45616329).

Almost surely, 2^121643542 is an apocalyptic number.

121643542 is a deficient number, since it is larger than the sum of its proper divisors (60821774).

121643542 is an equidigital number, since it uses as much as digits as its factorization.

121643542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60821773.

The product of its digits is 5760, while the sum is 28.

The square root of 121643542 is about 11029.2131178974. The cubic root of 121643542 is about 495.4840579982.

Adding to 121643542 its reverse (245346121), we get a palindrome (366989663).

The spelling of 121643542 in words is "one hundred twenty-one million, six hundred forty-three thousand, five hundred forty-two".