1938918399 has 12 divisors (see below), whose sum is σ = 2841610968. Its totient is φ = 1175101840.

The previous prime is 1938918349. The next prime is 1938918407. The reversal of 1938918399 is 9938198391.

It is not a de Polignac number, because 1938918399 - 2¹⁷ = 1938787327 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1938918349) 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, 2670324 + ... + 2671049.

It is an arithmetic number, because the mean of its divisors is an integer number (236800914).

Almost surely, 2^1938918399 is an apocalyptic number.

1938918399 is a deficient number, since it is larger than the sum of its proper divisors (902692569).

1938918399 is a wasteful number, since it uses less digits than its factorization.

1938918399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5341398 (or 5341387 counting only the distinct ones).

The product of its digits is 3779136, while the sum is 60.

The square root of 1938918399 is about 44033.1511363881. The cubic root of 1938918399 is about 1246.9618802986.

The spelling of 1938918399 in words is "one billion, nine hundred thirty-eight million, nine hundred eighteen thousand, three hundred ninety-nine".