8521720 has 16 divisors (see below), whose sum is σ = 19173960. Its totient is φ = 3408672.

The previous prime is 8521703. The next prime is 8521739. The reversal of 8521720 is 271258.

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, 106482 + ... + 106561.

Almost surely, 2^8521720 is an apocalyptic number.

It is an amenable number.

8521720 is an abundant number, since it is smaller than the sum of its proper divisors (10652240).

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

8521720 is a wasteful number, since it uses less digits than its factorization.

8521720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213054 (or 213050 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 8521720 is about 2919.1985201421. The cubic root of 8521720 is about 204.2564377309.

Adding to 8521720 its reverse (271258), we get a palindrome (8792978).

The spelling of 8521720 in words is "eight million, five hundred twenty-one thousand, seven hundred twenty".