1338717661 has 4 divisors (see below), whose sum is σ = 1352518972. Its totient is φ = 1324916352.

The previous prime is 1338717659. The next prime is 1338717697. The reversal of 1338717661 is 1667178331.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 961620100 + 377097561 = 31010^2 + 19419^2 .

It is a cyclic number.

It is not a de Polignac number, because 1338717661 - 2¹ = 1338717659 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1338717161) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6900510 + ... + 6900703.

It is an arithmetic number, because the mean of its divisors is an integer number (338129743).

Almost surely, 2^1338717661 is an apocalyptic number.

It is an amenable number.

1338717661 is a deficient number, since it is larger than the sum of its proper divisors (13801311).

1338717661 is an equidigital number, since it uses as much as digits as its factorization.

1338717661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13801310.

The product of its digits is 127008, while the sum is 43.

The square root of 1338717661 is about 36588.4908270347. The cubic root of 1338717661 is about 1102.1219813194.

The spelling of 1338717661 in words is "one billion, three hundred thirty-eight million, seven hundred seventeen thousand, six hundred sixty-one".