8720646 has 32 divisors (see below), whose sum is σ = 19305216. Its totient is φ = 2604000.

The previous prime is 8720629. The next prime is 8720671. The reversal of 8720646 is 6460278.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3756 + ... + 5616.

It is an arithmetic number, because the mean of its divisors is an integer number (603288).

Almost surely, 2^8720646 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8720646, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9652608).

8720646 is an abundant number, since it is smaller than the sum of its proper divisors (10584570).

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

8720646 is a wasteful number, since it uses less digits than its factorization.

8720646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1948.

The product of its (nonzero) digits is 16128, while the sum is 33.

The square root of 8720646 is about 2953.0739916230. The cubic root of 8720646 is about 205.8335759566.

The spelling of 8720646 in words is "eight million, seven hundred twenty thousand, six hundred forty-six".