521981648 has 20 divisors (see below), whose sum is σ = 1012118628. Its totient is φ = 260789760.

The previous prime is 521981639. The next prime is 521981653. The reversal of 521981648 is 846189125.

It can be written as a sum of positive squares in 2 ways, for example, as 435640384 + 86341264 = 20872^2 + 9292^2 .

It is a junction number, because it is equal to n+sod(n) for n = 521981599 and 521981608.

It is a congruent number.

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, 10088 + ... + 33848.

Almost surely, 2^521981648 is an apocalyptic number.

It is an amenable number.

521981648 is a deficient number, since it is larger than the sum of its proper divisors (490136980).

521981648 is a wasteful number, since it uses less digits than its factorization.

521981648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25142 (or 25136 counting only the distinct ones).

The product of its digits is 138240, while the sum is 44.

The square root of 521981648 is about 22846.9176914524. The cubic root of 521981648 is about 805.1653521424.

The spelling of 521981648 in words is "five hundred twenty-one million, nine hundred eighty-one thousand, six hundred forty-eight".