521663742 has 24 divisors (see below), whose sum is σ = 1147143816. Its totient is φ = 171292176.

The previous prime is 521663731. The next prime is 521663749. The reversal of 521663742 is 247366125.

521663742 is a `hidden beast` number, since 5 + 2 + 16 + 637 + 4 + 2 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 521663697 and 521663706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521663749) 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, 215073 + ... + 217484.

It is an arithmetic number, because the mean of its divisors is an integer number (47797659).

Almost surely, 2^521663742 is an apocalyptic number.

521663742 is an abundant number, since it is smaller than the sum of its proper divisors (625480074).

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

521663742 is a wasteful number, since it uses less digits than its factorization.

521663742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432632 (or 432629 counting only the distinct ones).

The product of its digits is 60480, while the sum is 36.

The square root of 521663742 is about 22839.9593257081. The cubic root of 521663742 is about 805.0018605206.

The spelling of 521663742 in words is "five hundred twenty-one million, six hundred sixty-three thousand, seven hundred forty-two".