20420645605635 has 64 divisors (see below), whose sum is σ = 35912218890240. Its totient is φ = 9826271364480.

The previous prime is 20420645605621. The next prime is 20420645605639. The reversal of 20420645605635 is 53650654602402.

It is not a de Polignac number, because 20420645605635 - 2⁵ = 20420645605603 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20420645605639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 66426952 + ... + 66733658.

It is an arithmetic number, because the mean of its divisors is an integer number (561128420160).

Almost surely, 2^{20420645605635} is an apocalyptic number.

20420645605635 is a deficient number, since it is larger than the sum of its proper divisors (15491573284605).

20420645605635 is a wasteful number, since it uses less digits than its factorization.

20420645605635 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309768.

The product of its (nonzero) digits is 5184000, while the sum is 48.

The spelling of 20420645605635 in words is "twenty trillion, four hundred twenty billion, six hundred forty-five million, six hundred five thousand, six hundred thirty-five".