21251435001513 has 16 divisors (see below), whose sum is σ = 30632699104320. Its totient is φ = 13059203299776.

The previous prime is 21251435001491. The next prime is 21251435001523. The reversal of 21251435001513 is 31510053415212.

It is not a de Polignac number, because 21251435001513 - 2²⁴ = 21251418224297 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21251435001523) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5038270770 + ... + 5038274987.

It is an arithmetic number, because the mean of its divisors is an integer number (1914543694020).

Almost surely, 2^{21251435001513} is an apocalyptic number.

It is an amenable number.

21251435001513 is a deficient number, since it is larger than the sum of its proper divisors (9381264102807).

21251435001513 is a wasteful number, since it uses less digits than its factorization.

21251435001513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10076545816.

The product of its (nonzero) digits is 18000, while the sum is 33.

Adding to 21251435001513 its reverse (31510053415212), we get a palindrome (52761488416725).

The spelling of 21251435001513 in words is "twenty-one trillion, two hundred fifty-one billion, four hundred thirty-five million, one thousand, five hundred thirteen".