9972865728 has 252 divisors, whose sum is σ = 33419277840. Its totient is φ = 2835108864.

The previous prime is 9972865699. The next prime is 9972865759. The reversal of 9972865728 is 8275682799.

It is a tau number, because it is divible by the number of its divisors (252).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 6462525 + ... + 6464067.

Almost surely, 2^9972865728 is an apocalyptic number.

9972865728 is a gapful number since it is divisible by the number (98) 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 9972865728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16709638920).

9972865728 is an abundant number, since it is smaller than the sum of its proper divisors (23446412112).

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

9972865728 is a wasteful number, since it uses less digits than its factorization.

9972865728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1804 (or 1784 counting only the distinct ones).

The product of its digits is 30481920, while the sum is 63.

The square root of 9972865728 is about 99864.2364813350. The cubic root of 9972865728 is about 2152.4842909819.

The spelling of 9972865728 in words is "nine billion, nine hundred seventy-two million, eight hundred sixty-five thousand, seven hundred twenty-eight".