20688512 has 32 divisors (see below), whose sum is σ = 44389380. Its totient is φ = 9547776.

The previous prime is 20688463. The next prime is 20688517. The reversal of 20688512 is 21588602.

It can be written as a sum of positive squares in 2 ways, for example, as 17505856 + 3182656 = 4184^2 + 1784^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is not an unprimeable number, because it can be changed into a prime (20688517) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4553 + ... + 7880.

Almost surely, 2^20688512 is an apocalyptic number.

It is an amenable number.

20688512 is an abundant number, since it is smaller than the sum of its proper divisors (23700868).

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

20688512 is a wasteful number, since it uses less digits than its factorization.

20688512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12460 (or 12448 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 32.

The square root of 20688512 is about 4548.4625974059. The cubic root of 20688512 is about 274.5215349566.

The spelling of 20688512 in words is "twenty million, six hundred eighty-eight thousand, five hundred twelve".