1239673681 has 9 divisors (see below), whose sum is σ = 1253666449. Its totient is φ = 1225836544.

The previous prime is 1239673667. The next prime is 1239673723. The reversal of 1239673681 is 1863769321.

The square root of 1239673681 is 35209.

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 574033681 + 665640000 = 23959^2 + 25800^2 .

It is not a de Polignac number, because 1239673681 - 2⁵ = 1239673649 is a prime.

It is a super-2 number, since 2×1239673681² = 3073581670728179522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1239673661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 4823505 + ... + 4823761.

Almost surely, 2^1239673681 is an apocalyptic number.

1239673681 is the 35209-th square number.

1239673681 is the 17605-th centered octagonal number.

It is an amenable number.

1239673681 is a deficient number, since it is larger than the sum of its proper divisors (13992768).

1239673681 is an frugal number, since it uses more digits than its factorization.

1239673681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 788 (or 394 counting only the distinct ones).

The product of its digits is 326592, while the sum is 46.

The cubic root of 1239673681 is about 1074.2428216998.

The spelling of 1239673681 in words is "one billion, two hundred thirty-nine million, six hundred seventy-three thousand, six hundred eighty-one".