9978520 has 16 divisors (see below), whose sum is σ = 22451760. Its totient is φ = 3991392.

The previous prime is 9978461. The next prime is 9978547. The reversal of 9978520 is 258799.

It is a super-2 number, since 2×9978520² = 199141722780800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40), and also a Moran number because the ratio is a prime number: 249463 = 9978520 / (9 + 9 + 7 + 8 + 5 + 2 + 0).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 124692 + ... + 124771.

It is an arithmetic number, because the mean of its divisors is an integer number (1403235).

Almost surely, 2^9978520 is an apocalyptic number.

It is an amenable number.

9978520 is an abundant number, since it is smaller than the sum of its proper divisors (12473240).

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

9978520 is a wasteful number, since it uses less digits than its factorization.

9978520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249474 (or 249470 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 40.

The square root of 9978520 is about 3158.8795481943. The cubic root of 9978520 is about 215.2891008990.

The spelling of 9978520 in words is "nine million, nine hundred seventy-eight thousand, five hundred twenty".