9920571840 has 168 divisors, whose sum is σ = 35918759760. Its totient is φ = 2506235904.

The previous prime is 9920571779. The next prime is 9920571841. The reversal of 9920571840 is 481750299.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9920571841) 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, 35929 + ... + 145368.

Almost surely, 2^9920571840 is an apocalyptic number.

9920571840 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 9920571840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17959379880).

9920571840 is an abundant number, since it is smaller than the sum of its proper divisors (25998187920).

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

9920571840 is a wasteful number, since it uses less digits than its factorization.

9920571840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181339 (or 181326 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 45.

The square root of 9920571840 is about 99602.0674484220. The cubic root of 9920571840 is about 2148.7154280738.

The spelling of 9920571840 in words is "nine billion, nine hundred twenty million, five hundred seventy-one thousand, eight hundred forty".