20990600 has 24 divisors (see below), whose sum is σ = 48803610. Its totient is φ = 8396160.

The previous prime is 20990591. The next prime is 20990603. The reversal of 20990600 is 609902.

It can be written as a sum of positive squares in 3 ways, for example, as 12545764 + 8444836 = 3542^2 + 2906^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20990600.

It is not an unprimeable number, because it can be changed into a prime (20990603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 52277 + ... + 52676.

Almost surely, 2^20990600 is an apocalyptic number.

20990600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20990600 is an abundant number, since it is smaller than the sum of its proper divisors (27813010).

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

20990600 is a wasteful number, since it uses less digits than its factorization.

20990600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104969 (or 104960 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 26.

The square root of 20990600 is about 4581.5499560738. The cubic root of 20990600 is about 275.8512465941.

It can be divided in two parts, 209 and 90600, that added together give a palindrome (90809).

The spelling of 20990600 in words is "twenty million, nine hundred ninety thousand, six hundred".