9997781528 has 32 divisors (see below), whose sum is σ = 21427904160. Its totient is φ = 4283946240.

The previous prime is 9997781527. The next prime is 9997781543. The reversal of 9997781528 is 8251877999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9997781527) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 348698 + ... + 376278.

It is an arithmetic number, because the mean of its divisors is an integer number (669622005).

Almost surely, 2^9997781528 is an apocalyptic number.

It is an amenable number.

9997781528 is an abundant number, since it is smaller than the sum of its proper divisors (11430122632).

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

9997781528 is a wasteful number, since it uses less digits than its factorization.

9997781528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34067 (or 34063 counting only the distinct ones).

The product of its digits is 22861440, while the sum is 65.

The square root of 9997781528 is about 99988.9070247295. The cubic root of 9997781528 is about 2154.2753598145.

The spelling of 9997781528 in words is "nine billion, nine hundred ninety-seven million, seven hundred eighty-one thousand, five hundred twenty-eight".