1817947945969 has 3 divisors (see below), whose sum is σ = 1817949294283. Its totient is φ = 1817946597656.

The previous prime is 1817947945949. The next prime is 1817947945981. The reversal of 1817947945969 is 9695497497181.

The square root of 1817947945969 is 1348313.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 1083649770225 + 734298175744 = 1040985^2 + 856912^2 .

It is not a de Polignac number, because 1817947945969 - 2¹¹ = 1817947943921 is a prime.

It is a super-2 number, since 2×1817947945969² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1817947945909) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 674157 + ... + 2022469.

Almost surely, 2^{1817947945969} is an apocalyptic number.

1817947945969 is the 1348313-rd square number.

1817947945969 is the 674157-th centered octagonal number.

It is an amenable number.

1817947945969 is a deficient number, since it is larger than the sum of its proper divisors (1348314).

1817947945969 is an frugal number, since it uses more digits than its factorization.

1817947945969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2696626 (or 1348313 counting only the distinct ones).

The product of its digits is 1234517760, while the sum is 79.

The spelling of 1817947945969 in words is "one trillion, eight hundred seventeen billion, nine hundred forty-seven million, nine hundred forty-five thousand, nine hundred sixty-nine".