21004551114555 has 16 divisors (see below), whose sum is σ = 33607383734304. Its totient is φ = 11202393277440.

The previous prime is 21004551114529. The next prime is 21004551114583. The reversal of 21004551114555 is 55541115540012.

It is not a de Polignac number, because 21004551114555 - 2¹⁰ = 21004551113531 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3458827 + ... + 7346603.

It is an arithmetic number, because the mean of its divisors is an integer number (2100461483394).

Almost surely, 2^{21004551114555} is an apocalyptic number.

21004551114555 is a deficient number, since it is larger than the sum of its proper divisors (12602832619749).

21004551114555 is a wasteful number, since it uses less digits than its factorization.

21004551114555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4247966.

The product of its (nonzero) digits is 100000, while the sum is 39.

Adding to 21004551114555 its reverse (55541115540012), we get a palindrome (76545666654567).

The spelling of 21004551114555 in words is "twenty-one trillion, four billion, five hundred fifty-one million, one hundred fourteen thousand, five hundred fifty-five".