780078989 has 4 divisors (see below), whose sum is σ = 782540124. Its totient is φ = 777617856.

The previous prime is 780078977. The next prime is 780079007. The reversal of 780078989 is 989870087.

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

It can be written as a sum of positive squares in 2 ways, for example, as 98346889 + 681732100 = 9917^2 + 26110^2 .

It is a cyclic number.

It is not a de Polignac number, because 780078989 - 2⁴ = 780078973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (780071989) 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 3 ways as a sum of consecutive naturals, for example, 1230092 + ... + 1230725.

It is an arithmetic number, because the mean of its divisors is an integer number (195635031).

Almost surely, 2^780078989 is an apocalyptic number.

It is an amenable number.

780078989 is a deficient number, since it is larger than the sum of its proper divisors (2461135).

780078989 is a wasteful number, since it uses less digits than its factorization.

780078989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2461134.

The product of its (nonzero) digits is 2032128, while the sum is 56.

The square root of 780078989 is about 27929.8941816828. The cubic root of 780078989 is about 920.5474801389.

The spelling of 780078989 in words is "seven hundred eighty million, seventy-eight thousand, nine hundred eighty-nine".