1338073781 has 12 divisors (see below), whose sum is σ = 1471992396. Its totient is φ = 1215424320.

The previous prime is 1338073777. The next prime is 1338073823. The reversal of 1338073781 is 1873708331.

It can be written as a sum of positive squares in 2 ways, for example, as 898500625 + 439573156 = 29975^2 + 20966^2 .

It is not a de Polignac number, because 1338073781 - 2² = 1338073777 is a prime.

It is a super-2 number, since 2×1338073781² = 3580882886799271922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1338073381) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 169535 + ... + 177251.

It is an arithmetic number, because the mean of its divisors is an integer number (122666033).

Almost surely, 2^1338073781 is an apocalyptic number.

1338073781 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1338073781 is a deficient number, since it is larger than the sum of its proper divisors (133918615).

1338073781 is a wasteful number, since it uses less digits than its factorization.

1338073781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9172 (or 9161 counting only the distinct ones).

The product of its (nonzero) digits is 84672, while the sum is 41.

The square root of 1338073781 is about 36579.6908270149. The cubic root of 1338073781 is about 1101.9452579463.

The spelling of 1338073781 in words is "one billion, three hundred thirty-eight million, seventy-three thousand, seven hundred eighty-one".