531155139985 has 4 divisors (see below), whose sum is σ = 637386167988. Its totient is φ = 424924111984.

The previous prime is 531155139979. The next prime is 531155139989. The reversal of 531155139985 is 589931551135.

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

It can be written as a sum of positive squares in 2 ways, for example, as 424785883536 + 106369256449 = 651756^2 + 326143^2 .

It is a cyclic number.

It is not a de Polignac number, because 531155139985 - 2²⁹ = 530618269073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (531155139989) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53115513994 + ... + 53115514003.

It is an arithmetic number, because the mean of its divisors is an integer number (159346541997).

Almost surely, 2^531155139985 is an apocalyptic number.

It is an amenable number.

531155139985 is a deficient number, since it is larger than the sum of its proper divisors (106231028003).

531155139985 is a wasteful number, since it uses less digits than its factorization.

531155139985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106231028002.

The product of its digits is 3645000, while the sum is 55.

The spelling of 531155139985 in words is "five hundred thirty-one billion, one hundred fifty-five million, one hundred thirty-nine thousand, nine hundred eighty-five".