8991720 has 48 divisors (see below), whose sum is σ = 29224260. Its totient is φ = 2397696.

The previous prime is 8991713. The next prime is 8991739. The reversal of 8991720 is 271998.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 7650756 + 1340964 = 2766^2 + 1158^2 .

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

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 12129 + ... + 12848.

Almost surely, 2^8991720 is an apocalyptic number.

It is an amenable number.

8991720 is an abundant number, since it is smaller than the sum of its proper divisors (20232540).

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

8991720 is a wasteful number, since it uses less digits than its factorization.

8991720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24994 (or 24987 counting only the distinct ones).

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

The square root of 8991720 is about 2998.6196824539. The cubic root of 8991720 is about 207.9445734959.

It can be divided in two parts, 89 and 91720, that added together give a square (91809 = 303²).

The spelling of 8991720 in words is "eight million, nine hundred ninety-one thousand, seven hundred twenty".