991793907 has 24 divisors (see below), whose sum is σ = 1551950400. Its totient is φ = 610322544.

The previous prime is 991793903. The next prime is 991793921. The reversal of 991793907 is 709397199.

It is not a de Polignac number, because 991793907 - 2² = 991793903 is a prime.

It is not an unprimeable number, because it can be changed into a prime (991793903) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5307 + ... + 44852.

It is an arithmetic number, because the mean of its divisors is an integer number (64664600).

Almost surely, 2^991793907 is an apocalyptic number.

991793907 is a deficient number, since it is larger than the sum of its proper divisors (560156493).

991793907 is a wasteful number, since it uses less digits than its factorization.

991793907 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50204 (or 50175 counting only the distinct ones).

The product of its (nonzero) digits is 964467, while the sum is 54.

The square root of 991793907 is about 31492.7595964533. The cubic root of 991793907 is about 997.2571191499.

The spelling of 991793907 in words is "nine hundred ninety-one million, seven hundred ninety-three thousand, nine hundred seven".