521216012420 has 12 divisors (see below), whose sum is σ = 1094553626124. Its totient is φ = 208486404960.

The previous prime is 521216012413. The next prime is 521216012453. The reversal of 521216012420 is 24210612125.

It can be written as a sum of positive squares in 2 ways, for example, as 257217351556 + 263998660864 = 507166^2 + 513808^2 .

It is a super-2 number, since 2×521216012420² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 521216012420.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13030400291 + ... + 13030400330.

It is an arithmetic number, because the mean of its divisors is an integer number (91212802177).

Almost surely, 2^521216012420 is an apocalyptic number.

It is an amenable number.

521216012420 is an abundant number, since it is smaller than the sum of its proper divisors (573337613704).

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

521216012420 is a wasteful number, since it uses less digits than its factorization.

521216012420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26060800630 (or 26060800628 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 26.

Adding to 521216012420 its reverse (24210612125), we get a palindrome (545426624545).

The spelling of 521216012420 in words is "five hundred twenty-one billion, two hundred sixteen million, twelve thousand, four hundred twenty".