20500020 has 48 divisors (see below), whose sum is σ = 63779520. Its totient is φ = 5466528.

The previous prime is 20500019. The next prime is 20500027. The reversal of 20500020 is 2000502.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 20499975 and 20500011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20500027) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18442 + ... + 19521.

It is an arithmetic number, because the mean of its divisors is an integer number (1328740).

Almost surely, 2^20500020 is an apocalyptic number.

20500020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20500020 is an abundant number, since it is smaller than the sum of its proper divisors (43279500).

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

20500020 is a wasteful number, since it uses less digits than its factorization.

20500020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37981 (or 37973 counting only the distinct ones).

The product of its (nonzero) digits is 20, while the sum is 9.

The square root of 20500020 is about 4527.6947776987. The cubic root of 20500020 is about 273.6852727432.

Adding to 20500020 its reverse (2000502), we get a palindrome (22500522).

The spelling of 20500020 in words is "twenty million, five hundred thousand, twenty".