20420644240020 has 96 divisors (see below), whose sum is σ = 61683491132928. Its totient is φ = 5028479752192.

The previous prime is 20420644240001. The next prime is 20420644240021. The reversal of 20420644240020 is 2004244602402.

It is a super-2 number, since 2×20420644240020² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a self number, because there is not a number n which added to its sum of digits gives 20420644240020.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20420644240021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 188816124 + ... + 188924243.

It is an arithmetic number, because the mean of its divisors is an integer number (642536365968).

Almost surely, 2^{20420644240020} is an apocalyptic number.

20420644240020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20420644240020 is an abundant number, since it is smaller than the sum of its proper divisors (41262846892908).

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

20420644240020 is a wasteful number, since it uses less digits than its factorization.

20420644240020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 377740449 (or 377740447 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 30.

Adding to 20420644240020 its reverse (2004244602402), we get a palindrome (22424888842422).

The spelling of 20420644240020 in words is "twenty trillion, four hundred twenty billion, six hundred forty-four million, two hundred forty thousand, twenty".