784080991 has 2 divisors, whose sum is σ = 784080992. Its totient is φ = 784080990.

The previous prime is 784080977. The next prime is 784081013. The reversal of 784080991 is 199080487.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (199080487) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 784080991 - 2⁷ = 784080863 is a prime.

It is a super-2 number, since 2×784080991² = 1229566000895084162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (784000991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 392040495 + 392040496.

It is an arithmetic number, because the mean of its divisors is an integer number (392040496).

Almost surely, 2^784080991 is an apocalyptic number.

784080991 is a deficient number, since it is larger than the sum of its proper divisors (1).

784080991 is an equidigital number, since it uses as much as digits as its factorization.

784080991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145152, while the sum is 46.

The square root of 784080991 is about 28001.4462305075. The cubic root of 784080991 is about 922.1190093461.

It can be divided in two parts, 7840 and 80991, that added together give a triangular number (88831 = T₄₂₁).

The spelling of 784080991 in words is "seven hundred eighty-four million, eighty thousand, nine hundred ninety-one".