20040020 has 162 divisors, whose sum is σ = 58267566. Its totient is φ = 5765760.

The previous prime is 20039993. The next prime is 20040049. The reversal of 20040020 is 2004002.

It can be written as a sum of positive squares in 3 ways, for example, as 94864 + 19945156 = 308^2 + 4466^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 1541534 + ... + 1541546.

Almost surely, 2^20040020 is an apocalyptic number.

20040020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20040020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29133783).

20040020 is an abundant number, since it is smaller than the sum of its proper divisors (38227546).

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

20040020 is a wasteful number, since it uses less digits than its factorization.

20040020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71 (or 38 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 8.

The square root of 20040020 is about 4476.6080909546. The cubic root of 20040020 is about 271.6226926871.

Adding to 20040020 its reverse (2004002), we get a palindrome (22044022).

The spelling of 20040020 in words is "twenty million, forty thousand, twenty".