9865951395840 has 360 divisors, whose sum is σ = 35304258382848. Its totient is φ = 2546046074880.

The previous prime is 9865951395827. The next prime is 9865951395841. The reversal of 9865951395840 is 485931595689.

9865951395840 is a `hidden beast` number, since 9 + 8 + 6 + 5 + 9 + 5 + 1 + 39 + 584 + 0 = 666.

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

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9865951395841) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22639849 + ... + 23071511.

Almost surely, 2^{9865951395840} is an apocalyptic number.

9865951395840 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 9865951395840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17652129191424).

9865951395840 is an abundant number, since it is smaller than the sum of its proper divisors (25438306987008).

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

9865951395840 is a wasteful number, since it uses less digits than its factorization.

9865951395840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431733 (or 431704 counting only the distinct ones).

The product of its (nonzero) digits is 419904000, while the sum is 72.

The spelling of 9865951395840 in words is "nine trillion, eight hundred sixty-five billion, nine hundred fifty-one million, three hundred ninety-five thousand, eight hundred forty".