213123556165 has 8 divisors (see below), whose sum is σ = 275421211128. Its totient is φ = 157383549120.

The previous prime is 213123556049. The next prime is 213123556171. The reversal of 213123556165 is 561655321312.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 20263807201 + 192859748964 = 142351^2 + 439158^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-213123556165 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1639411906 + ... + 1639412035.

It is an arithmetic number, because the mean of its divisors is an integer number (34427651391).

Almost surely, 2^213123556165 is an apocalyptic number.

It is an amenable number.

213123556165 is a deficient number, since it is larger than the sum of its proper divisors (62297654963).

213123556165 is a wasteful number, since it uses less digits than its factorization.

213123556165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3278823959.

The product of its digits is 162000, while the sum is 40.

Adding to 213123556165 its reverse (561655321312), we get a palindrome (774778877477).

The spelling of 213123556165 in words is "two hundred thirteen billion, one hundred twenty-three million, five hundred fifty-six thousand, one hundred sixty-five".