1338090721 has 6 divisors (see below), whose sum is σ = 1470794066. Its totient is φ = 1216446000.

The previous prime is 1338090697. The next prime is 1338090731. The reversal of 1338090721 is 1270908331.

It can be written as a sum of positive squares in only one way, i.e., 1270209600 + 67881121 = 35640^2 + 8239^2 .

It is not a de Polignac number, because 1338090721 - 2¹¹ = 1338088673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1338090731) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5529180 + ... + 5529421.

Almost surely, 2^1338090721 is an apocalyptic number.

1338090721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1338090721 is a deficient number, since it is larger than the sum of its proper divisors (132703345).

1338090721 is a wasteful number, since it uses less digits than its factorization.

1338090721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11058623 (or 11058612 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 34.

The square root of 1338090721 is about 36579.9223755327. The cubic root of 1338090721 is about 1101.9499081318.

The spelling of 1338090721 in words is "one billion, three hundred thirty-eight million, ninety thousand, seven hundred twenty-one".