20695840 has 72 divisors (see below), whose sum is σ = 53793180. Its totient is φ = 7518720.

The previous prime is 20695819. The next prime is 20695847. The reversal of 20695840 is 4859602.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20539024 + 156816 = 4532^2 + 396^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20695796 and 20695805.

It is not an unprimeable number, because it can be changed into a prime (20695847) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18826 + ... + 19894.

Almost surely, 2^20695840 is an apocalyptic number.

20695840 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 20695840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26896590).

20695840 is an abundant number, since it is smaller than the sum of its proper divisors (33097340).

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

20695840 is a wasteful number, since it uses less digits than its factorization.

20695840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1106 (or 1087 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 20695840 is about 4549.2680729981. The cubic root of 20695840 is about 274.5539435438.

The spelling of 20695840 in words is "twenty million, six hundred ninety-five thousand, eight hundred forty".