20659400 has 48 divisors (see below), whose sum is σ = 48964500. Its totient is φ = 8103680.

The previous prime is 20659391. The next prime is 20659409. The reversal of 20659400 is 495602.

It is an interprime number because it is at equal distance from previous prime (20659391) and next prime (20659409).

It can be written as a sum of positive squares in 6 ways, for example, as 13118884 + 7540516 = 3622^2 + 2746^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20659400.

It is not an unprimeable number, because it can be changed into a prime (20659409) 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 11 ways as a sum of consecutive naturals, for example, 9626 + ... + 11574.

Almost surely, 2^20659400 is an apocalyptic number.

20659400 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 20659400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24482250).

20659400 is an abundant number, since it is smaller than the sum of its proper divisors (28305100).

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

20659400 is a wasteful number, since it uses less digits than its factorization.

20659400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2018 (or 2009 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 20659400 is about 4545.2612686181. The cubic root of 20659400 is about 274.3927094766.

The spelling of 20659400 in words is "twenty million, six hundred fifty-nine thousand, four hundred".