991676243 has 2 divisors, whose sum is σ = 991676244. Its totient is φ = 991676242.

The previous prime is 991676209. The next prime is 991676261. The reversal of 991676243 is 342676199.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (342676199) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 991676243 - 2²² = 987481939 is a prime.

It is not a weakly prime, because it can be changed into another prime (991676293) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495838121 + 495838122.

It is an arithmetic number, because the mean of its divisors is an integer number (495838122).

Almost surely, 2^991676243 is an apocalyptic number.

991676243 is a deficient number, since it is larger than the sum of its proper divisors (1).

991676243 is an equidigital number, since it uses as much as digits as its factorization.

991676243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 489888, while the sum is 47.

The square root of 991676243 is about 31490.8914291101. The cubic root of 991676243 is about 997.2176802095.

The spelling of 991676243 in words is "nine hundred ninety-one million, six hundred seventy-six thousand, two hundred forty-three".