999451791 has 20 divisors (see below), whose sum is σ = 1607856712. Its totient is φ = 615046608.

The previous prime is 999451787. The next prime is 999451801. The reversal of 999451791 is 197154999.

It is not a de Polignac number, because 999451791 - 2² = 999451787 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999451741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 473521 + ... + 475626.

Almost surely, 2^999451791 is an apocalyptic number.

999451791 is a deficient number, since it is larger than the sum of its proper divisors (608404921).

999451791 is a wasteful number, since it uses less digits than its factorization.

999451791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 949172 (or 949163 counting only the distinct ones).

The product of its digits is 918540, while the sum is 54.

The square root of 999451791 is about 31614.1074680276. The cubic root of 999451791 is about 999.8172302639.

The spelling of 999451791 in words is "nine hundred ninety-nine million, four hundred fifty-one thousand, seven hundred ninety-one".