20000020 has 24 divisors (see below), whose sum is σ = 42420168. Its totient is φ = 7920000.

The previous prime is 20000003. The next prime is 20000023. The reversal of 20000020 is 2000002.

It can be written as a sum of positive squares in 4 ways, for example, as 12404484 + 7595536 = 3522^2 + 2756^2 .

It is a Harshad number since it is a multiple of its sum of digits (4).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a junction number, because it is equal to n+sod(n) for n = 19999964 and 20000009.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20000023) 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, 2931 + ... + 6970.

It is an arithmetic number, because the mean of its divisors is an integer number (1767507).

Almost surely, 2^20000020 is an apocalyptic number.

20000020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20000020 is an abundant number, since it is smaller than the sum of its proper divisors (22420148).

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

20000020 is a wasteful number, since it uses less digits than its factorization.

20000020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10011 (or 10009 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 4.

The square root of 20000020 is about 4472.1381910670. The cubic root of 20000020 is about 271.4418521400.

Adding to 20000020 its reverse (2000002), we get a palindrome (22000022).

It can be divided in two parts, 200000 and 20, that multiplied together give a square (4000000 = 2000²).

The spelling of 20000020 in words is "twenty million, twenty", and thus it is an aban number and an uban number.