521651212212 has 96 divisors (see below), whose sum is σ = 1345295831040. Its totient is φ = 156340517760.

The previous prime is 521651212127. The next prime is 521651212219. The reversal of 521651212212 is 212212156125.

It is a self number, because there is not a number n which added to its sum of digits gives 521651212212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521651212219) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 635589 + ... + 1203027.

It is an arithmetic number, because the mean of its divisors is an integer number (14013498240).

Almost surely, 2^521651212212 is an apocalyptic number.

521651212212 is a gapful number since it is divisible by the number (52) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 521651212212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (672647915520).

521651212212 is an abundant number, since it is smaller than the sum of its proper divisors (823644618828).

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

521651212212 is a wasteful number, since it uses less digits than its factorization.

521651212212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 567613 (or 567611 counting only the distinct ones).

The product of its digits is 4800, while the sum is 30.

Adding to 521651212212 its reverse (212212156125), we get a palindrome (733863368337).

The spelling of 521651212212 in words is "five hundred twenty-one billion, six hundred fifty-one million, two hundred twelve thousand, two hundred twelve".