542643312665 has 16 divisors (see below), whose sum is σ = 655191468048. Its totient is φ = 431443224576.

The previous prime is 542643312619. The next prime is 542643312667. The reversal of 542643312665 is 566213346245.

It can be written as a sum of positive squares in 8 ways, for example, as 150126026521 + 392517286144 = 387461^2 + 626512^2 .

It is a cyclic number.

It is not a de Polignac number, because 542643312665 - 2¹² = 542643308569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (542643312667) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12959 + ... + 1041851.

It is an arithmetic number, because the mean of its divisors is an integer number (40949466753).

Almost surely, 2^542643312665 is an apocalyptic number.

It is an amenable number.

542643312665 is a deficient number, since it is larger than the sum of its proper divisors (112548155383).

542643312665 is a wasteful number, since it uses less digits than its factorization.

542643312665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1029548.

The product of its digits is 3110400, while the sum is 47.

The spelling of 542643312665 in words is "five hundred forty-two billion, six hundred forty-three million, three hundred twelve thousand, six hundred sixty-five".