285601991 has 2 divisors, whose sum is σ = 285601992. Its totient is φ = 285601990.

The previous prime is 285601961. The next prime is 285601999. The reversal of 285601991 is 199106582.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-285601991 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (285601999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 142800995 + 142800996.

It is an arithmetic number, because the mean of its divisors is an integer number (142800996).

Almost surely, 2^285601991 is an apocalyptic number.

285601991 is a deficient number, since it is larger than the sum of its proper divisors (1).

285601991 is an equidigital number, since it uses as much as digits as its factorization.

285601991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 38880, while the sum is 41.

The square root of 285601991 is about 16899.7630456761. The cubic root of 285601991 is about 658.5474567636.

The spelling of 285601991 in words is "two hundred eighty-five million, six hundred one thousand, nine hundred ninety-one".