8021520 has 120 divisors (see below), whose sum is σ = 29045016. Its totient is φ = 1972224.

The previous prime is 8021471. The next prime is 8021539. The reversal of 8021520 is 251208.

It can be written as a sum of positive squares in 4 ways, for example, as 1115136 + 6906384 = 1056^2 + 2628^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×8021520² = 128689566220800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 8021493 and 8021502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8932 + ... + 9788.

Almost surely, 2^8021520 is an apocalyptic number.

8021520 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8021520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14522508).

8021520 is an abundant number, since it is smaller than the sum of its proper divisors (21023496).

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

8021520 is a wasteful number, since it uses less digits than its factorization.

8021520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 889 (or 880 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 8021520 is about 2832.2288043165. The cubic root of 8021520 is about 200.1791727710.

Adding to 8021520 its reverse (251208), we get a palindrome (8272728).

The spelling of 8021520 in words is "eight million, twenty-one thousand, five hundred twenty".