1231378938 has 12 divisors (see below), whose sum is σ = 2667987738. Its totient is φ = 410459640.

The previous prime is 1231378933. The next prime is 1231378943. The reversal of 1231378938 is 8398731321.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1231378933) and next prime (1231378943).

It can be written as a sum of positive squares in only one way, i.e., 866301489 + 365077449 = 29433^2 + 19107^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1231378893 and 1231378902.

It is not an unprimeable number, because it can be changed into a prime (1231378933) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 34204953 + ... + 34204988.

Almost surely, 2^1231378938 is an apocalyptic number.

1231378938 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1231378938 is an abundant number, since it is smaller than the sum of its proper divisors (1436608800).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1231378938 is a wasteful number, since it uses less digits than its factorization.

1231378938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68409949 (or 68409946 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 1231378938 is about 35091.0093613735. The cubic root of 1231378938 is about 1071.8415134056.

The spelling of 1231378938 in words is "one billion, two hundred thirty-one million, three hundred seventy-eight thousand, nine hundred thirty-eight".