20204820 has 36 divisors (see below), whose sum is σ = 61288500. Its totient is φ = 5387904.

The previous prime is 20204813. The next prime is 20204827. The reversal of 20204820 is 2840202.

It is an interprime number because it is at equal distance from previous prime (20204813) and next prime (20204827).

It can be written as a sum of positive squares in 2 ways, for example, as 13793796 + 6411024 = 3714^2 + 2532^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 20204793 and 20204802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20204827) 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, 55945 + ... + 56304.

Almost surely, 2^20204820 is an apocalyptic number.

20204820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20204820 is an abundant number, since it is smaller than the sum of its proper divisors (41083680).

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

20204820 is a wasteful number, since it uses less digits than its factorization.

20204820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112264 (or 112259 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 20204820 is about 4494.9771968276. The cubic root of 20204820 is about 272.3652280843.

The spelling of 20204820 in words is "twenty million, two hundred four thousand, eight hundred twenty".