21481659513 has 28 divisors (see below), whose sum is σ = 32241790548. Its totient is φ = 14305973760.

The previous prime is 21481659499. The next prime is 21481659523. The reversal of 21481659513 is 31595618412.

It is a happy number.

21481659513 is a `hidden beast` number, since 2 + 1 + 4 + 81 + 6 + 59 + 513 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 18805459689 + 2676199824 = 137133^2 + 51732^2 .

It is not a de Polignac number, because 21481659513 - 2⁶ = 21481659449 is a prime.

It is a super-2 number, since 2×21481659513² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21481659523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 697153 + ... + 727313.

Almost surely, 2^21481659513 is an apocalyptic number.

It is an amenable number.

21481659513 is a deficient number, since it is larger than the sum of its proper divisors (10760131035).

21481659513 is an frugal number, since it uses more digits than its factorization.

21481659513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31156 (or 31141 counting only the distinct ones).

The product of its digits is 259200, while the sum is 45.

It can be divided in two parts, 2148 and 1659513, that added together give a palindrome (1661661).

The spelling of 21481659513 in words is "twenty-one billion, four hundred eighty-one million, six hundred fifty-nine thousand, five hundred thirteen".