20864420 has 12 divisors (see below), whose sum is σ = 43815324. Its totient is φ = 8345760.

The previous prime is 20864387. The next prime is 20864429. The reversal of 20864420 is 2446802.

It can be written as a sum of positive squares in 2 ways, for example, as 14684224 + 6180196 = 3832^2 + 2486^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20864420.

It is not an unprimeable number, because it can be changed into a prime (20864429) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 521591 + ... + 521630.

It is an arithmetic number, because the mean of its divisors is an integer number (3651277).

Almost surely, 2^20864420 is an apocalyptic number.

20864420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20864420 is an abundant number, since it is smaller than the sum of its proper divisors (22950904).

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

20864420 is a wasteful number, since it uses less digits than its factorization.

20864420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1043230 (or 1043228 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 26.

The square root of 20864420 is about 4567.7587501969. The cubic root of 20864420 is about 275.2973972736.

The spelling of 20864420 in words is "twenty million, eight hundred sixty-four thousand, four hundred twenty".