999997440 has 240 divisors, whose sum is σ = 3457049568. Its totient is φ = 245366784.

The previous prime is 999997403. The next prime is 999997457. The reversal of 999997440 is 44799999.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a nialpdrome in base 10.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3194724 + ... + 3195036.

Almost surely, 2^999997440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 999997440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1728524784).

999997440 is an abundant number, since it is smaller than the sum of its proper divisors (2457052128).

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

999997440 is a wasteful number, since it uses less digits than its factorization.

999997440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 362 (or 336 counting only the distinct ones).

The product of its (nonzero) digits is 6613488, while the sum is 60.

The square root of 999997440 is about 31622.7361245038. The cubic root of 999997440 is about 999.9991466659. Note that the first 3 decimals are identical.

The spelling of 999997440 in words is "nine hundred ninety-nine million, nine hundred ninety-seven thousand, four hundred forty".