20820500 has 24 divisors (see below), whose sum is σ = 45473064. Its totient is φ = 8328000.

The previous prime is 20820491. The next prime is 20820509. The reversal of 20820500 is 502802.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20820491) and next prime (20820509).

It can be written as a sum of positive squares in 4 ways, for example, as 498436 + 20322064 = 706^2 + 4508^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20820509) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20321 + ... + 21320.

It is an arithmetic number, because the mean of its divisors is an integer number (1894711).

Almost surely, 2^20820500 is an apocalyptic number.

20820500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20820500 is an abundant number, since it is smaller than the sum of its proper divisors (24652564).

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

20820500 is a wasteful number, since it uses less digits than its factorization.

20820500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41660 (or 41648 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 20820500 is about 4562.9486080823. The cubic root of 20820500 is about 275.1040928253.

The spelling of 20820500 in words is "twenty million, eight hundred twenty thousand, five hundred".