9915840 has 168 divisors, whose sum is σ = 37325808. Its totient is φ = 2396160.

The previous prime is 9915833. The next prime is 9915847. The reversal of 9915840 is 485199.

It is an interprime number because it is at equal distance from previous prime (9915833) and next prime (9915847).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 9915795 and 9915804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9915847) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 31524 + ... + 31836.

Almost surely, 2^9915840 is an apocalyptic number.

9915840 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9915840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18662904).

9915840 is an abundant number, since it is smaller than the sum of its proper divisors (27409968).

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

9915840 is a wasteful number, since it uses less digits than its factorization.

9915840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 347 (or 334 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 9915840 is about 3148.9426796942. The cubic root of 9915840 is about 214.8373747684.

It can be divided in two parts, 9 and 915840, that added together give a square (915849 = 957²).

The spelling of 9915840 in words is "nine million, nine hundred fifteen thousand, eight hundred forty".