991294238 has 16 divisors (see below), whose sum is σ = 1625683824. Its totient is φ = 449597760.

The previous prime is 991294231. The next prime is 991294243. The reversal of 991294238 is 832492199.

It is a junction number, because it is equal to n+sod(n) for n = 991294192 and 991294201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991294231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39245 + ... + 59352.

It is an arithmetic number, because the mean of its divisors is an integer number (101605239).

Almost surely, 2^991294238 is an apocalyptic number.

991294238 is a deficient number, since it is larger than the sum of its proper divisors (634389586).

991294238 is a wasteful number, since it uses less digits than its factorization.

991294238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99067.

The product of its digits is 279936, while the sum is 47.

The square root of 991294238 is about 31484.8255196055. The cubic root of 991294238 is about 997.0896172227.

The spelling of 991294238 in words is "nine hundred ninety-one million, two hundred ninety-four thousand, two hundred thirty-eight".