991495667 has 2 divisors, whose sum is σ = 991495668. Its totient is φ = 991495666.

The previous prime is 991495643. The next prime is 991495669. The reversal of 991495667 is 766594199.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 991495667 - 2¹⁰ = 991494643 is a prime.

Together with 991495669, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (991495669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495747833 + 495747834.

It is an arithmetic number, because the mean of its divisors is an integer number (495747834).

Almost surely, 2^991495667 is an apocalyptic number.

991495667 is a deficient number, since it is larger than the sum of its proper divisors (1).

991495667 is an equidigital number, since it uses as much as digits as its factorization.

991495667 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3674160, while the sum is 56.

The square root of 991495667 is about 31488.0241838068. The cubic root of 991495667 is about 997.1571481854.

The spelling of 991495667 in words is "nine hundred ninety-one million, four hundred ninety-five thousand, six hundred sixty-seven".