997305918 has 96 divisors (see below), whose sum is σ = 2523615264. Its totient is φ = 260886528.

The previous prime is 997305917. The next prime is 997305937. The reversal of 997305918 is 819503799.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997305917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 182230 + ... + 187622.

It is an arithmetic number, because the mean of its divisors is an integer number (26287659).

Almost surely, 2^997305918 is an apocalyptic number.

997305918 is a gapful number since it is divisible by the number (98) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 997305918, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1261807632).

997305918 is an abundant number, since it is smaller than the sum of its proper divisors (1526309346).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

997305918 is a wasteful number, since it uses less digits than its factorization.

997305918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5466 (or 5459 counting only the distinct ones).

The product of its (nonzero) digits is 612360, while the sum is 51.

The square root of 997305918 is about 31580.1506962839. The cubic root of 997305918 is about 999.1011650044.

The spelling of 997305918 in words is "nine hundred ninety-seven million, three hundred five thousand, nine hundred eighteen".