8720945 has 8 divisors (see below), whose sum is σ = 10608936. Its totient is φ = 6880896.

The previous prime is 8720941. The next prime is 8720947. The reversal of 8720945 is 5490278.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2825761 + 5895184 = 1681^2 + 2428^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 8720945 - 2² = 8720941 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (8720941) 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, 11582 + ... + 12311.

It is an arithmetic number, because the mean of its divisors is an integer number (1326117).

Almost surely, 2^8720945 is an apocalyptic number.

It is an amenable number.

8720945 is a deficient number, since it is larger than the sum of its proper divisors (1887991).

8720945 is a wasteful number, since it uses less digits than its factorization.

8720945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23971.

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 8720945 is about 2953.1246164021. The cubic root of 8720945 is about 205.8359283640.

The spelling of 8720945 in words is "eight million, seven hundred twenty thousand, nine hundred forty-five".