991610783 has 2 divisors, whose sum is σ = 991610784. Its totient is φ = 991610782.

The previous prime is 991610777. The next prime is 991610791. The reversal of 991610783 is 387016199.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 991610783 - 2¹⁴ = 991594399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (991610723) 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 as a sum of consecutive naturals, namely, 495805391 + 495805392.

It is an arithmetic number, because the mean of its divisors is an integer number (495805392).

Almost surely, 2^991610783 is an apocalyptic number.

991610783 is a deficient number, since it is larger than the sum of its proper divisors (1).

991610783 is an equidigital number, since it uses as much as digits as its factorization.

991610783 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 81648, while the sum is 44.

The square root of 991610783 is about 31489.8520637999. The cubic root of 991610783 is about 997.1957377976.

The spelling of 991610783 in words is "nine hundred ninety-one million, six hundred ten thousand, seven hundred eighty-three".