21004042053 has 16 divisors (see below), whose sum is σ = 28148498432. Its totient is φ = 13931190000.

The previous prime is 21004042027. The next prime is 21004042061. The reversal of 21004042053 is 35024040012.

It is not a de Polignac number, because 21004042053 - 2²⁵ = 20970487621 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21004042013) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 2560188 + ... + 2568378.

It is an arithmetic number, because the mean of its divisors is an integer number (1759281152).

Almost surely, 2^21004042053 is an apocalyptic number.

It is an amenable number.

21004042053 is a deficient number, since it is larger than the sum of its proper divisors (7144456379).

21004042053 is a wasteful number, since it uses less digits than its factorization.

21004042053 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12456.

The product of its (nonzero) digits is 960, while the sum is 21.

Adding to 21004042053 its reverse (35024040012), we get a palindrome (56028082065).

The spelling of 21004042053 in words is "twenty-one billion, four million, forty-two thousand, fifty-three".