991619149 has 2 divisors, whose sum is σ = 991619150. Its totient is φ = 991619148.

The previous prime is 991619147. The next prime is 991619249. The reversal of 991619149 is 941916199.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 986588100 + 5031049 = 31410^2 + 2243^2 .

It is a cyclic number.

It is not a de Polignac number, because 991619149 - 2¹ = 991619147 is a prime.

Together with 991619147, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (991619141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495809574 + 495809575.

It is an arithmetic number, because the mean of its divisors is an integer number (495809575).

Almost surely, 2^991619149 is an apocalyptic number.

It is an amenable number.

991619149 is a deficient number, since it is larger than the sum of its proper divisors (1).

991619149 is an equidigital number, since it uses as much as digits as its factorization.

991619149 is an evil number, because the sum of its binary digits is even.

The product of its digits is 157464, while the sum is 49.

The square root of 991619149 is about 31489.9848999646. The cubic root of 991619149 is about 997.1985421628.

The spelling of 991619149 in words is "nine hundred ninety-one million, six hundred nineteen thousand, one hundred forty-nine".