521866642 has 16 divisors (see below), whose sum is σ = 891093312. Its totient is φ = 226898320.

The previous prime is 521866637. The next prime is 521866649. The reversal of 521866642 is 246668125.

It is a junction number, because it is equal to n+sod(n) for n = 521866595 and 521866604.

It is not an unprimeable number, because it can be changed into a prime (521866649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 515173 + ... + 516184.

It is an arithmetic number, because the mean of its divisors is an integer number (55693332).

Almost surely, 2^521866642 is an apocalyptic number.

521866642 is a deficient number, since it is larger than the sum of its proper divisors (369226670).

521866642 is a wasteful number, since it uses less digits than its factorization.

521866642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1031393.

The product of its digits is 138240, while the sum is 40.

The square root of 521866642 is about 22844.4006706239. The cubic root of 521866642 is about 805.1062149113.

The spelling of 521866642 in words is "five hundred twenty-one million, eight hundred sixty-six thousand, six hundred forty-two".