1938638550931 has 2 divisors, whose sum is σ = 1938638550932. Its totient is φ = 1938638550930.

The previous prime is 1938638550913. The next prime is 1938638550943. The reversal of 1938638550931 is 1390558368391.

Together with previous prime (1938638550913) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1938638550931 - 2⁵ = 1938638550899 is a prime.

It is a super-2 number, since 2×1938638550931² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1938638550931.

It is not a weakly prime, because it can be changed into another prime (1938638556931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 969319275465 + 969319275466.

It is an arithmetic number, because the mean of its divisors is an integer number (969319275466).

Almost surely, 2^{1938638550931} is an apocalyptic number.

1938638550931 is a deficient number, since it is larger than the sum of its proper divisors (1).

1938638550931 is an equidigital number, since it uses as much as digits as its factorization.

1938638550931 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20995200, while the sum is 61.

The spelling of 1938638550931 in words is "one trillion, nine hundred thirty-eight billion, six hundred thirty-eight million, five hundred fifty thousand, nine hundred thirty-one".