1216690623369 has 27 divisors (see below), whose sum is σ = 1903096211367. Its totient is φ = 748706218416.

The previous prime is 1216690623331. The next prime is 1216690623371. The reversal of 1216690623369 is 9633260966121.

The square root of 1216690623369 is 1103037.

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

1216690623369 is a `hidden beast` number, since 1 + 2 + 1 + 6 + 6 + 9 + 0 + 623 + 3 + 6 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 179983820025 + 1036706803344 = 424245^2 + 1018188^2 .

It is not a de Polignac number, because 1216690623369 - 2¹³ = 1216690615177 is a prime.

It is a super-3 number, since 3×1216690623369³ (a number of 37 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (1216690623389) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 43004302 + ... + 43032584.

Almost surely, 2^{1216690623369} is an apocalyptic number.

1216690623369 is the 1103037-th square number.

1216690623369 is the 551519-th centered octagonal number.

It is an amenable number.

1216690623369 is a deficient number, since it is larger than the sum of its proper divisors (686405587998).

1216690623369 is an frugal number, since it uses more digits than its factorization.

1216690623369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56598 (or 28299 counting only the distinct ones).

The product of its (nonzero) digits is 3779136, while the sum is 54.

The spelling of 1216690623369 in words is "one trillion, two hundred sixteen billion, six hundred ninety million, six hundred twenty-three thousand, three hundred sixty-nine".