245659991 has 2 divisors, whose sum is σ = 245659992. Its totient is φ = 245659990.

The previous prime is 245659963. The next prime is 245660003. The reversal of 245659991 is 199956542.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-245659991 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 (245659951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 122829995 + 122829996.

It is an arithmetic number, because the mean of its divisors is an integer number (122829996).

Almost surely, 2^245659991 is an apocalyptic number.

245659991 is a deficient number, since it is larger than the sum of its proper divisors (1).

245659991 is an equidigital number, since it uses as much as digits as its factorization.

245659991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 874800, while the sum is 50.

The square root of 245659991 is about 15673.5443024225. The cubic root of 245659991 is about 626.2938453478.

The spelling of 245659991 in words is "two hundred forty-five million, six hundred fifty-nine thousand, nine hundred ninety-one".