8561920 has 36 divisors (see below), whose sum is σ = 20511540. Its totient is φ = 3424256.

The previous prime is 8561909. The next prime is 8561939. The reversal of 8561920 is 291658.

It can be written as a sum of positive squares in 2 ways, for example, as 5234944 + 3326976 = 2288^2 + 1824^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2065 + ... + 4624.

It is an arithmetic number, because the mean of its divisors is an integer number (569765).

Almost surely, 2^8561920 is an apocalyptic number.

8561920 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

8561920 is an abundant number, since it is smaller than the sum of its proper divisors (11949620).

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

8561920 is an equidigital number, since it uses as much as digits as its factorization.

8561920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6710 (or 6696 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 8561920 is about 2926.0758705133. The cubic root of 8561920 is about 204.5771175526.

The spelling of 8561920 in words is "eight million, five hundred sixty-one thousand, nine hundred twenty".