20400505510555 has 16 divisors (see below), whose sum is σ = 27284886629280. Its totient is φ = 14551939533312.

The previous prime is 20400505510543. The next prime is 20400505510621. The reversal of 20400505510555 is 55501550500402.

It is not a de Polignac number, because 20400505510555 - 2⁵ = 20400505510523 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6315944364 + ... + 6315947593.

It is an arithmetic number, because the mean of its divisors is an integer number (1705305414330).

Almost surely, 2^{20400505510555} is an apocalyptic number.

20400505510555 is a deficient number, since it is larger than the sum of its proper divisors (6884381118725).

20400505510555 is a wasteful number, since it uses less digits than its factorization.

20400505510555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12631891998.

The product of its (nonzero) digits is 125000, while the sum is 37.

The spelling of 20400505510555 in words is "twenty trillion, four hundred billion, five hundred five million, five hundred ten thousand, five hundred fifty-five".