20648520 has 80 divisors (see below), whose sum is σ = 69412860. Its totient is φ = 5505408.

The previous prime is 20648501. The next prime is 20648527. The reversal of 20648520 is 2584602.

It can be written as a sum of positive squares in 2 ways, for example, as 20412324 + 236196 = 4518^2 + 486^2 .

It is a super-2 number, since 2×20648520² = 852722756380800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20648527) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 54 + ... + 6426.

Almost surely, 2^20648520 is an apocalyptic number.

20648520 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 20648520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34706430).

20648520 is an abundant number, since it is smaller than the sum of its proper divisors (48764340).

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

20648520 is a wasteful number, since it uses less digits than its factorization.

20648520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6396 (or 6383 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 20648520 is about 4544.0642601090. The cubic root of 20648520 is about 274.3445325869.

The spelling of 20648520 in words is "twenty million, six hundred forty-eight thousand, five hundred twenty".