15823378135321 has 9 divisors (see below), whose sum is σ = 16218894430749. Its totient is φ = 15437282968800.

The previous prime is 15823378135303. The next prime is 15823378135387. The reversal of 15823378135321 is 12353187332851.

The square root of 15823378135321 is 3977861.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 10218321885321 + 5605056250000 = 3196611^2 + 2367500^2 .

It is a de Polignac number, because none of the positive numbers 2^k-15823378135321 is a prime.

It is a super-2 number, since 2×15823378135321² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15823378135421) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 163043791 + ... + 163140811.

Almost surely, 2^{15823378135321} is an apocalyptic number.

15823378135321 is the 3977861-st square number.

15823378135321 is the 1988931-st centered octagonal number.

It is an amenable number.

15823378135321 is a deficient number, since it is larger than the sum of its proper divisors (395516295428).

15823378135321 is an frugal number, since it uses more digits than its factorization.

15823378135321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194124 (or 97062 counting only the distinct ones).

The product of its digits is 3628800, while the sum is 52.

The spelling of 15823378135321 in words is "fifteen trillion, eight hundred twenty-three billion, three hundred seventy-eight million, one hundred thirty-five thousand, three hundred twenty-one".