9972001800 has 384 divisors, whose sum is σ = 36622656000. Its totient is φ = 2486764800.

The previous prime is 9972001783. The next prime is 9972001801. The reversal of 9972001800 is 81002799.

It is a happy number.

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

It is not an unprimeable number, because it can be changed into a prime (9972001801) 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 95 ways as a sum of consecutive naturals, for example, 8515215 + ... + 8516385.

It is an arithmetic number, because the mean of its divisors is an integer number (95371500).

Almost surely, 2^9972001800 is an apocalyptic number.

9972001800 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 9972001800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18311328000).

9972001800 is an abundant number, since it is smaller than the sum of its proper divisors (26650654200).

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

9972001800 is a wasteful number, since it uses less digits than its factorization.

9972001800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1298 (or 1283 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 9972001800 is about 99859.9108751855. The cubic root of 9972001800 is about 2152.4221341523.

The spelling of 9972001800 in words is "nine billion, nine hundred seventy-two million, one thousand, eight hundred".