521013645 has 12 divisors (see below), whose sum is σ = 903090396. Its totient is φ = 277873920.

The previous prime is 521013643. The next prime is 521013673. The reversal of 521013645 is 546310125.

521013645 is a `hidden beast` number, since 5 + 2 + 1 + 0 + 13 + 645 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 161645796 + 359367849 = 12714^2 + 18957^2 .

It is not a de Polignac number, because 521013645 - 2¹ = 521013643 is a prime.

It is a super-3 number, since 3×521013645³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521013643) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5788996 + ... + 5789085.

It is an arithmetic number, because the mean of its divisors is an integer number (75257533).

Almost surely, 2^521013645 is an apocalyptic number.

It is an amenable number.

521013645 is a deficient number, since it is larger than the sum of its proper divisors (382076751).

521013645 is a wasteful number, since it uses less digits than its factorization.

521013645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11578092 (or 11578089 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 521013645 is about 22825.7233182215. The cubic root of 521013645 is about 804.6673239256.

The spelling of 521013645 in words is "five hundred twenty-one million, thirteen thousand, six hundred forty-five".