121780423 has 4 divisors (see below), whose sum is σ = 127075248. Its totient is φ = 116485600.

The previous prime is 121780403. The next prime is 121780441. The reversal of 121780423 is 324087121.

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-121780423 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121780391 and 121780400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121780403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2647378 + ... + 2647423.

It is an arithmetic number, because the mean of its divisors is an integer number (31768812).

Almost surely, 2^121780423 is an apocalyptic number.

121780423 is a deficient number, since it is larger than the sum of its proper divisors (5294825).

121780423 is an equidigital number, since it uses as much as digits as its factorization.

121780423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5294824.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 121780423 is about 11035.4167569694. The cubic root of 121780423 is about 495.6698383221.

The spelling of 121780423 in words is "one hundred twenty-one million, seven hundred eighty thousand, four hundred twenty-three".