991190143 has 2 divisors, whose sum is σ = 991190144. Its totient is φ = 991190142.

The previous prime is 991190087. The next prime is 991190173. The reversal of 991190143 is 341091199.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 991190143 - 2¹³ = 991181951 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (991190173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495595071 + 495595072.

It is an arithmetic number, because the mean of its divisors is an integer number (495595072).

Almost surely, 2^991190143 is an apocalyptic number.

991190143 is a deficient number, since it is larger than the sum of its proper divisors (1).

991190143 is an equidigital number, since it uses as much as digits as its factorization.

991190143 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8748, while the sum is 37.

The square root of 991190143 is about 31483.1723782722. The cubic root of 991190143 is about 997.0547148117.

The spelling of 991190143 in words is "nine hundred ninety-one million, one hundred ninety thousand, one hundred forty-three".