20645324562520 has 128 divisors (see below), whose sum is σ = 53957222899200. Its totient is φ = 6963009371136.

The previous prime is 20645324562497. The next prime is 20645324562529. The reversal of 20645324562520 is 2526542354602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20645324562529) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6414247 + ... + 9079273.

It is an arithmetic number, because the mean of its divisors is an integer number (421540803900).

Almost surely, 2^{20645324562520} is an apocalyptic number.

20645324562520 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 20645324562520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26978611449600).

20645324562520 is an abundant number, since it is smaller than the sum of its proper divisors (33311898336680).

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

20645324562520 is a wasteful number, since it uses less digits than its factorization.

20645324562520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2665497 (or 2665493 counting only the distinct ones).

The product of its (nonzero) digits is 3456000, while the sum is 46.

The spelling of 20645324562520 in words is "twenty trillion, six hundred forty-five billion, three hundred twenty-four million, five hundred sixty-two thousand, five hundred twenty".