21537425520013 has 32 divisors (see below), whose sum is σ = 23681769261696. Its totient is φ = 19466594915328.

The previous prime is 21537425520011. The next prime is 21537425520067. The reversal of 21537425520013 is 31002552473512.

It is a cyclic number.

It is not a de Polignac number, because 21537425520013 - 2¹ = 21537425520011 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21537425520011) 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 31 ways as a sum of consecutive naturals, for example, 119037145 + ... + 119217937.

It is an arithmetic number, because the mean of its divisors is an integer number (740055289428).

Almost surely, 2^{21537425520013} is an apocalyptic number.

It is an amenable number.

21537425520013 is a deficient number, since it is larger than the sum of its proper divisors (2144343741683).

21537425520013 is a wasteful number, since it uses less digits than its factorization.

21537425520013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181693.

The product of its (nonzero) digits is 252000, while the sum is 40.

Adding to 21537425520013 its reverse (31002552473512), we get a palindrome (52539977993525).

The spelling of 21537425520013 in words is "twenty-one trillion, five hundred thirty-seven billion, four hundred twenty-five million, five hundred twenty thousand, thirteen".