780680991 has 4 divisors (see below), whose sum is σ = 1040907992. Its totient is φ = 520453992.

The previous prime is 780680977. The next prime is 780680993. The reversal of 780680991 is 199086087.

It is a happy number.

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

It is not a de Polignac number, because 780680991 - 2⁷ = 780680863 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 780680991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (780680993) 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, 130113496 + ... + 130113501.

It is an arithmetic number, because the mean of its divisors is an integer number (260226998).

Almost surely, 2^780680991 is an apocalyptic number.

780680991 is a deficient number, since it is larger than the sum of its proper divisors (260227001).

780680991 is a wasteful number, since it uses less digits than its factorization.

780680991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260227000.

The product of its (nonzero) digits is 217728, while the sum is 48.

The square root of 780680991 is about 27940.6691222669. The cubic root of 780680991 is about 920.7842206648.

The spelling of 780680991 in words is "seven hundred eighty million, six hundred eighty thousand, nine hundred ninety-one".