20585664 has 210 divisors, whose sum is σ = 70257924. Its totient is φ = 5909760.

The previous prime is 20585659. The next prime is 20585687. The reversal of 20585664 is 46658502.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 1083447 + ... + 1083465.

Almost surely, 2^20585664 is an apocalyptic number.

20585664 is a gapful number since it is divisible by the number (24) 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 20585664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35128962).

20585664 is an abundant number, since it is smaller than the sum of its proper divisors (49672260).

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

20585664 is a wasteful number, since it uses less digits than its factorization.

20585664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73 (or 35 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The square root of 20585664 is about 4537.1427132062. The cubic root of 20585664 is about 274.0658729503.

The spelling of 20585664 in words is "twenty million, five hundred eighty-five thousand, six hundred sixty-four".