20862640 has 40 divisors (see below), whose sum is σ = 49202208. Its totient is φ = 8225280.

The previous prime is 20862637. The next prime is 20862643. The reversal of 20862640 is 4626802.

It is an interprime number because it is at equal distance from previous prime (20862637) and next prime (20862643).

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 20862599 and 20862608.

It is not an unprimeable number, because it can be changed into a prime (20862643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3844 + ... + 7516.

Almost surely, 2^20862640 is an apocalyptic number.

20862640 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 20862640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24601104).

20862640 is an abundant number, since it is smaller than the sum of its proper divisors (28339568).

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

20862640 is a wasteful number, since it uses less digits than its factorization.

20862640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3757 (or 3751 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 20862640 is about 4567.5639021255. The cubic root of 20862640 is about 275.2895682629.

The spelling of 20862640 in words is "twenty million, eight hundred sixty-two thousand, six hundred forty".