21520421001053 has 24 divisors (see below), whose sum is σ = 24727245936768. Its totient is φ = 18656092046592.

The previous prime is 21520421000993. The next prime is 21520421001089. The reversal of 21520421001053 is 35010012402512.

It is not a de Polignac number, because 21520421001053 - 2²⁰ = 21520419952477 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21520421001853) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 6758975 + ... + 9419372.

It is an arithmetic number, because the mean of its divisors is an integer number (1030301914032).

Almost surely, 2^{21520421001053} is an apocalyptic number.

It is an amenable number.

21520421001053 is a deficient number, since it is larger than the sum of its proper divisors (3206824935715).

21520421001053 is a wasteful number, since it uses less digits than its factorization.

21520421001053 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16178853 (or 16178840 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 26.

Adding to 21520421001053 its reverse (35010012402512), we get a palindrome (56530433403565).

The spelling of 21520421001053 in words is "twenty-one trillion, five hundred twenty billion, four hundred twenty-one million, one thousand, fifty-three".