9990872820 has 72 divisors (see below), whose sum is σ = 31283266560. Its totient is φ = 2578288320.

The previous prime is 9990872819. The next prime is 9990872831. The reversal of 9990872820 is 282780999.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 889660 + ... + 900819.

Almost surely, 2^9990872820 is an apocalyptic number.

9990872820 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

9990872820 is an abundant number, since it is smaller than the sum of its proper divisors (21292393740).

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

9990872820 is a wasteful number, since it uses less digits than its factorization.

9990872820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1790525 (or 1790520 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 54.

The square root of 9990872820 is about 99954.3536820683. The cubic root of 9990872820 is about 2153.7790267390.

The spelling of 9990872820 in words is "nine billion, nine hundred ninety million, eight hundred seventy-two thousand, eight hundred twenty".