1381939845 has 32 divisors (see below), whose sum is σ = 2597664384. Its totient is φ = 618489600.

The previous prime is 1381939841. The next prime is 1381939879. The reversal of 1381939845 is 5489391831.

It is not a de Polignac number, because 1381939845 - 2² = 1381939841 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1381939841) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 319986 + ... + 324275.

It is an arithmetic number, because the mean of its divisors is an integer number (81177012).

Almost surely, 2^1381939845 is an apocalyptic number.

1381939845 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1381939845 is a deficient number, since it is larger than the sum of its proper divisors (1215724539).

1381939845 is a wasteful number, since it uses less digits than its factorization.

1381939845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 644293.

The product of its digits is 933120, while the sum is 51.

The square root of 1381939845 is about 37174.4515090674. The cubic root of 1381939845 is about 1113.8577039017.

The spelling of 1381939845 in words is "one billion, three hundred eighty-one million, nine hundred thirty-nine thousand, eight hundred forty-five".