785920991 has 4 divisors (see below), whose sum is σ = 787424232. Its totient is φ = 784417752.

The previous prime is 785920987. The next prime is 785921039. The reversal of 785920991 is 199029587.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 785920991 - 2² = 785920987 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 (785920951) 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, 750836 + ... + 751881.

It is an arithmetic number, because the mean of its divisors is an integer number (196856058).

Almost surely, 2^785920991 is an apocalyptic number.

785920991 is a deficient number, since it is larger than the sum of its proper divisors (1503241).

785920991 is a wasteful number, since it uses less digits than its factorization.

785920991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1503240.

The product of its (nonzero) digits is 408240, while the sum is 50.

The square root of 785920991 is about 28034.2824234900. The cubic root of 785920991 is about 922.8397569524.

The spelling of 785920991 in words is "seven hundred eighty-five million, nine hundred twenty thousand, nine hundred ninety-one".