783720991 has 2 divisors, whose sum is σ = 783720992. Its totient is φ = 783720990.

The previous prime is 783720989. The next prime is 783720997. The reversal of 783720991 is 199027387.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 783720991 - 2¹ = 783720989 is a prime.

It is a super-2 number, since 2×783720991² = 1228437183468044162, which contains 22 as substring.

Together with 783720989, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (783720997) 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 as a sum of consecutive naturals, namely, 391860495 + 391860496.

It is an arithmetic number, because the mean of its divisors is an integer number (391860496).

Almost surely, 2^783720991 is an apocalyptic number.

783720991 is a deficient number, since it is larger than the sum of its proper divisors (1).

783720991 is an equidigital number, since it uses as much as digits as its factorization.

783720991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 190512, while the sum is 46.

The square root of 783720991 is about 27995.0172530756. The cubic root of 783720991 is about 921.9778616562.

The spelling of 783720991 in words is "seven hundred eighty-three million, seven hundred twenty thousand, nine hundred ninety-one".