121561343999 has 8 divisors (see below), whose sum is σ = 122528967168. Its totient is φ = 120593884320.

The previous prime is 121561343971. The next prime is 121561344001. The reversal of 121561343999 is 999343165121.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121561343999 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121561343999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121561343599) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1769309 + ... + 1836729.

It is an arithmetic number, because the mean of its divisors is an integer number (15316120896).

Almost surely, 2^121561343999 is an apocalyptic number.

121561343999 is a deficient number, since it is larger than the sum of its proper divisors (967623169).

121561343999 is a wasteful number, since it uses less digits than its factorization.

121561343999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81745.

The product of its digits is 1574640, while the sum is 53.

The spelling of 121561343999 in words is "one hundred twenty-one billion, five hundred sixty-one million, three hundred forty-three thousand, nine hundred ninety-nine".