20006520 has 64 divisors (see below), whose sum is σ = 62100000. Its totient is φ = 5150208.

The previous prime is 20006509. The next prime is 20006531. The reversal of 20006520 is 2560002.

It is an interprime number because it is at equal distance from previous prime (20006509) and next prime (20006531).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 20006520.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 606 + ... + 6354.

Almost surely, 2^20006520 is an apocalyptic number.

20006520 is a gapful number since it is divisible by the number (20) 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 20006520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31050000).

20006520 is an abundant number, since it is smaller than the sum of its proper divisors (42093480).

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

20006520 is a wasteful number, since it uses less digits than its factorization.

20006520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5792 (or 5788 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 15.

The square root of 20006520 is about 4472.8648537598. The cubic root of 20006520 is about 271.4712551262.

Adding to 20006520 its reverse (2560002), we get a palindrome (22566522).

The spelling of 20006520 in words is "twenty million, six thousand, five hundred twenty".