21530505214520 has 64 divisors (see below), whose sum is σ = 48472801513920. Its totient is φ = 8607018824704.

The previous prime is 21530505214513. The next prime is 21530505214591. The reversal of 21530505214520 is 2541250503512.

It is a happy number.

It is a super-2 number, since 2×21530505214520² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 509058494 + ... + 509100786.

It is an arithmetic number, because the mean of its divisors is an integer number (757387523655).

Almost surely, 2^{21530505214520} is an apocalyptic number.

21530505214520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21530505214520 is an abundant number, since it is smaller than the sum of its proper divisors (26942296299400).

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

21530505214520 is a wasteful number, since it uses less digits than its factorization.

21530505214520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49664 (or 49660 counting only the distinct ones).

The product of its (nonzero) digits is 60000, while the sum is 35.

The spelling of 21530505214520 in words is "twenty-one trillion, five hundred thirty billion, five hundred five million, two hundred fourteen thousand, five hundred twenty".