20520400000005 has 28 divisors (see below), whose sum is σ = 36919830788460. Its totient is φ = 10944213331392.

The previous prime is 20520399999973. The next prime is 20520400000019. The reversal of 20520400000005 is 50000000402502.

It can be written as a sum of positive squares in 2 ways, for example, as 3315308998401 + 17205091001604 = 1820799^2 + 4147902^2 .

It is not a de Polignac number, because 20520400000005 - 2⁵ = 20520399999973 is a prime.

It is a congruent number.

It is an unprimeable number.

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 27 ways as a sum of consecutive naturals, for example, 2814866040 + ... + 2814873329.

Almost surely, 2^{20520400000005} is an apocalyptic number.

It is an amenable number.

20520400000005 is a deficient number, since it is larger than the sum of its proper divisors (16399430788455).

20520400000005 is an frugal number, since it uses more digits than its factorization.

20520400000005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5629739392 (or 5629739377 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 18.

Adding to 20520400000005 its reverse (50000000402502), we get a palindrome (70520400402507).

The spelling of 20520400000005 in words is "twenty trillion, five hundred twenty billion, four hundred million, five", and thus it is an aban number.