121780219 has 4 divisors (see below), whose sum is σ = 132851160. Its totient is φ = 110709280.

The previous prime is 121780207. The next prime is 121780223. The reversal of 121780219 is 912087121.

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

It is not a de Polignac number, because 121780219 - 2⁵ = 121780187 is a prime.

It is a super-2 number, since 2×121780219² = 29660843479375922, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121780229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5535454 + ... + 5535475.

It is an arithmetic number, because the mean of its divisors is an integer number (33212790).

Almost surely, 2^121780219 is an apocalyptic number.

121780219 is a deficient number, since it is larger than the sum of its proper divisors (11070941).

121780219 is a wasteful number, since it uses less digits than its factorization.

121780219 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11070940.

The product of its (nonzero) digits is 2016, while the sum is 31.

The square root of 121780219 is about 11035.4075139978. The cubic root of 121780219 is about 495.6695615488.

The spelling of 121780219 in words is "one hundred twenty-one million, seven hundred eighty thousand, two hundred nineteen".