20440640664642 has 32 divisors (see below), whose sum is σ = 44694502864704. Its totient is φ = 6180697227200.

The previous prime is 20440640664629. The next prime is 20440640664643. The reversal of 20440640664642 is 24646604604402.

It is a super-2 number, since 2×20440640664642² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20440640664591 and 20440640664600.

It is not an unprimeable number, because it can be changed into a prime (20440640664643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 335877033 + ... + 335937884.

It is an arithmetic number, because the mean of its divisors is an integer number (1396703214522).

Almost surely, 2^{20440640664642} is an apocalyptic number.

20440640664642 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

20440640664642 is an abundant number, since it is smaller than the sum of its proper divisors (24253862200062).

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

20440640664642 is a wasteful number, since it uses less digits than its factorization.

20440640664642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 671815394.

The product of its (nonzero) digits is 5308416, while the sum is 48.

The spelling of 20440640664642 in words is "twenty trillion, four hundred forty billion, six hundred forty million, six hundred sixty-four thousand, six hundred forty-two".