531138821366 has 4 divisors (see below), whose sum is σ = 796708232052. Its totient is φ = 265569410682.

The previous prime is 531138821363. The next prime is 531138821387. The reversal of 531138821366 is 663128831135.

It is a semiprime because it is the product of two primes.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 531138821366.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (531138821363) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 132784705340 + ... + 132784705343.

It is an arithmetic number, because the mean of its divisors is an integer number (199177058013).

Almost surely, 2^531138821366 is an apocalyptic number.

531138821366 is a deficient number, since it is larger than the sum of its proper divisors (265569410686).

531138821366 is a wasteful number, since it uses less digits than its factorization.

531138821366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265569410685.

The product of its digits is 622080, while the sum is 47.

The spelling of 531138821366 in words is "five hundred thirty-one billion, one hundred thirty-eight million, eight hundred twenty-one thousand, three hundred sixty-six".