20705136 has 80 divisors (see below), whose sum is σ = 57258240. Its totient is φ = 6428160.

The previous prime is 20705131. The next prime is 20705137. The reversal of 20705136 is 63150702.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20705131) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 66421 + ... + 66731.

It is an arithmetic number, because the mean of its divisors is an integer number (715728).

Almost surely, 2^20705136 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 20705136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28629120).

20705136 is an abundant number, since it is smaller than the sum of its proper divisors (36553104).

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

20705136 is a wasteful number, since it uses less digits than its factorization.

20705136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414 (or 408 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 24.

The square root of 20705136 is about 4550.2896611095. The cubic root of 20705136 is about 274.5950447413.

Adding to 20705136 its reverse (63150702), we get a palindrome (83855838).

The spelling of 20705136 in words is "twenty million, seven hundred five thousand, one hundred thirty-six".