21487100445 has 40 divisors (see below), whose sum is σ = 40783372344. Its totient is φ = 10785678336.

The previous prime is 21487100441. The next prime is 21487100491. The reversal of 21487100445 is 54400178412.

It is a happy number.

21487100445 is a `hidden beast` number, since 2 + 148 + 71 + 0 + 0 + 445 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 6544971801 + 14942128644 = 80901^2 + 122238^2 .

It is not a de Polignac number, because 21487100445 - 2² = 21487100441 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21487100441) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1553544 + ... + 1567313.

Almost surely, 2^21487100445 is an apocalyptic number.

It is an amenable number.

21487100445 is a deficient number, since it is larger than the sum of its proper divisors (19296271899).

21487100445 is a wasteful number, since it uses less digits than its factorization.

21487100445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3120891 (or 3120882 counting only the distinct ones).

The product of its (nonzero) digits is 35840, while the sum is 36.

Adding to 21487100445 its reverse (54400178412), we get a palindrome (75887278857).

The spelling of 21487100445 in words is "twenty-one billion, four hundred eighty-seven million, one hundred thousand, four hundred forty-five".