21500236007445 has 48 divisors (see below), whose sum is σ = 37307689471872. Its totient is φ = 10568371057920.

The previous prime is 21500236007441. The next prime is 21500236007489. The reversal of 21500236007445 is 54470063200512.

It is not a de Polignac number, because 21500236007445 - 2² = 21500236007441 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21500236007441) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4914226 + ... + 8194515.

It is an arithmetic number, because the mean of its divisors is an integer number (777243530664).

Almost surely, 2^{21500236007445} is an apocalyptic number.

It is an amenable number.

21500236007445 is a deficient number, since it is larger than the sum of its proper divisors (15807453464427).

21500236007445 is a wasteful number, since it uses less digits than its factorization.

21500236007445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13109422 (or 13109409 counting only the distinct ones).

The product of its (nonzero) digits is 201600, while the sum is 39.

Adding to 21500236007445 its reverse (54470063200512), we get a palindrome (75970299207957).

The spelling of 21500236007445 in words is "twenty-one trillion, five hundred billion, two hundred thirty-six million, seven thousand, four hundred forty-five".