8731220 has 24 divisors (see below), whose sum is σ = 18683784. Its totient is φ = 3426176.

The previous prime is 8731213. The next prime is 8731231. The reversal of 8731220 is 221378.

It can be written as a sum of positive squares in 4 ways, for example, as 2033476 + 6697744 = 1426^2 + 2588^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3059 + ... + 5178.

It is an arithmetic number, because the mean of its divisors is an integer number (778491).

Almost surely, 2^8731220 is an apocalyptic number.

It is an amenable number.

8731220 is an abundant number, since it is smaller than the sum of its proper divisors (9952564).

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

8731220 is a wasteful number, since it uses less digits than its factorization.

8731220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8299 (or 8297 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 8731220 is about 2954.8637870467. The cubic root of 8731220 is about 205.9167351302.

Adding to 8731220 its reverse (221378), we get a palindrome (8952598).

The spelling of 8731220 in words is "eight million, seven hundred thirty-one thousand, two hundred twenty".