521171385648 has 40 divisors (see below), whose sum is σ = 1346388492288. Its totient is φ = 173720043072.

The previous prime is 521171385619. The next prime is 521171385671. The reversal of 521171385648 is 846583171125.

It is a super-2 number, since 2×521171385648² (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 521171385648.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 2961865 + ... + 3132887.

Almost surely, 2^521171385648 is an apocalyptic number.

It is an amenable number.

521171385648 is an abundant number, since it is smaller than the sum of its proper divisors (825217106640).

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

521171385648 is a wasteful number, since it uses less digits than its factorization.

521171385648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234521 (or 234515 counting only the distinct ones).

The product of its digits is 1612800, while the sum is 51.

The spelling of 521171385648 in words is "five hundred twenty-one billion, one hundred seventy-one million, three hundred eighty-five thousand, six hundred forty-eight".