121617857543 has 8 divisors (see below), whose sum is σ = 149683517088. Its totient is φ = 96225117984.

The previous prime is 121617857539. The next prime is 121617857561. The reversal of 121617857543 is 345758716121.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 121617857543 - 2² = 121617857539 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 121617857491 and 121617857500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121617857563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 668229896 + ... + 668230077.

It is an arithmetic number, because the mean of its divisors is an integer number (18710439636).

Almost surely, 2^121617857543 is an apocalyptic number.

121617857543 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

121617857543 is a deficient number, since it is larger than the sum of its proper divisors (28065659545).

121617857543 is a wasteful number, since it uses less digits than its factorization.

121617857543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1336459993.

The product of its digits is 1411200, while the sum is 50.

It can be divided in two parts, 1216178 and 57543, that added together give a palindrome (1273721).

The spelling of 121617857543 in words is "one hundred twenty-one billion, six hundred seventeen million, eight hundred fifty-seven thousand, five hundred forty-three".