9959964656400 has 360 divisors, whose sum is σ = 37782879732000. Its totient is φ = 2409614592000.

The previous prime is 9959964656399. The next prime is 9959964656441. The reversal of 9959964656400 is 46564699599.

9959964656400 is a `hidden beast` number, since 9 + 9 + 59 + 9 + 6 + 4 + 6 + 564 + 0 + 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 an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 19187476 + ... + 19699724.

It is an arithmetic number, because the mean of its divisors is an integer number (104952443700).

Almost surely, 2^{9959964656400} is an apocalyptic number.

9959964656400 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 9959964656400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18891439866000).

9959964656400 is an abundant number, since it is smaller than the sum of its proper divisors (27822915075600).

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

9959964656400 is a wasteful number, since it uses less digits than its factorization.

9959964656400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 512775 (or 512761 counting only the distinct ones).

The product of its (nonzero) digits is 566870400, while the sum is 72.

The spelling of 9959964656400 in words is "nine trillion, nine hundred fifty-nine billion, nine hundred sixty-four million, six hundred fifty-six thousand, four hundred".