825603991 has 2 divisors, whose sum is σ = 825603992. Its totient is φ = 825603990.

The previous prime is 825603971. The next prime is 825604037. The reversal of 825603991 is 199306528.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 825603991 - 2⁵ = 825603959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (825603901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 412801995 + 412801996.

It is an arithmetic number, because the mean of its divisors is an integer number (412801996).

Almost surely, 2^825603991 is an apocalyptic number.

825603991 is a deficient number, since it is larger than the sum of its proper divisors (1).

825603991 is an equidigital number, since it uses as much as digits as its factorization.

825603991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 116640, while the sum is 43.

The square root of 825603991 is about 28733.3254427677. The cubic root of 825603991 is about 938.1175511847.

The spelling of 825603991 in words is "eight hundred twenty-five million, six hundred three thousand, nine hundred ninety-one".