21415304520 has 48 divisors (see below), whose sum is σ = 69599740860. Its totient is φ = 5710747776.

The previous prime is 21415304513. The next prime is 21415304527. The reversal of 21415304520 is 2540351412.

It is an interprime number because it is at equal distance from previous prime (21415304513) and next prime (21415304527).

It can be written as a sum of positive squares in 2 ways, for example, as 21175488324 + 239816196 = 145518^2 + 15486^2 .

It is not an unprimeable number, because it can be changed into a prime (21415304527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 29743119 + ... + 29743838.

Almost surely, 2^21415304520 is an apocalyptic number.

21415304520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21415304520 is an abundant number, since it is smaller than the sum of its proper divisors (48184436340).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21415304520 is a wasteful number, since it uses less digits than its factorization.

21415304520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59486974 (or 59486967 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

Adding to 21415304520 its reverse (2540351412), we get a palindrome (23955655932).

The spelling of 21415304520 in words is "twenty-one billion, four hundred fifteen million, three hundred four thousand, five hundred twenty".