9866157840 has 360 divisors, whose sum is σ = 42049058688. Its totient is φ = 2050030080.

The previous prime is 9866157839. The next prime is 9866157841. The reversal of 9866157840 is 487516689.

9866157840 is a `hidden beast` number, since 9 + 8 + 6 + 61 + 578 + 4 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (9866157839) and next prime (9866157841).

It is a tau number, because it is divible by the number of its divisors (360).

It is not an unprimeable number, because it can be changed into a prime (9866157841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 375369 + ... + 400791.

Almost surely, 2^9866157840 is an apocalyptic number.

9866157840 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 9866157840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21024529344).

9866157840 is an abundant number, since it is smaller than the sum of its proper divisors (32182900848).

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

9866157840 is a wasteful number, since it uses less digits than its factorization.

9866157840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25467 (or 25451 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 54.

The square root of 9866157840 is about 99328.5348729155. The cubic root of 9866157840 is about 2144.7796797199.

The spelling of 9866157840 in words is "nine billion, eight hundred sixty-six million, one hundred fifty-seven thousand, eight hundred forty".