20535680 has 64 divisors (see below), whose sum is σ = 53574480. Its totient is φ = 7464960.

The previous prime is 20535661. The next prime is 20535689. The reversal of 20535680 is 8653502.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20535689) 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, 5582 + ... + 8498.

Almost surely, 2^20535680 is an apocalyptic number.

20535680 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 20535680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26787240).

20535680 is an abundant number, since it is smaller than the sum of its proper divisors (33038800).

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

20535680 is a wasteful number, since it uses less digits than its factorization.

20535680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2947 (or 2935 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 20535680 is about 4531.6310529433. The cubic root of 20535680 is about 273.8438736178.

The spelling of 20535680 in words is "twenty million, five hundred thirty-five thousand, six hundred eighty".