20715648 has 64 divisors (see below), whose sum is σ = 55855200. Its totient is φ = 6801408.

The previous prime is 20715647. The next prime is 20715649. The reversal of 20715648 is 84651702.

It is an interprime number because it is at equal distance from previous prime (20715647) and next prime (20715649).

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-3 number, since 3×20715648³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20715641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27663 + ... + 28401.

Almost surely, 2^20715648 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20715648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27927600).

20715648 is an abundant number, since it is smaller than the sum of its proper divisors (35139552).

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

20715648 is an equidigital number, since it uses as much as digits as its factorization.

20715648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 829 (or 817 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 20715648 is about 4551.4446058367. Note that the first 3 decimals coincide. The cubic root of 20715648 is about 274.6415075247.

The spelling of 20715648 in words is "twenty million, seven hundred fifteen thousand, six hundred forty-eight".