20639444008340 has 12 divisors (see below), whose sum is σ = 43342832417556. Its totient is φ = 8255777603328.

The previous prime is 20639444008321. The next prime is 20639444008349. The reversal of 20639444008340 is 4380044493602.

It can be written as a sum of positive squares in 2 ways, for example, as 2400770511364 + 18238673496976 = 1549442^2 + 4270676^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20639444008349) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 515986100189 + ... + 515986100228.

It is an arithmetic number, because the mean of its divisors is an integer number (3611902701463).

Almost surely, 2^{20639444008340} is an apocalyptic number.

20639444008340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20639444008340 is an abundant number, since it is smaller than the sum of its proper divisors (22703388409216).

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

20639444008340 is a wasteful number, since it uses less digits than its factorization.

20639444008340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1031972200426 (or 1031972200424 counting only the distinct ones).

The product of its (nonzero) digits is 1990656, while the sum is 47.

The spelling of 20639444008340 in words is "twenty trillion, six hundred thirty-nine billion, four hundred forty-four million, eight thousand, three hundred forty".