1438117391 has 4 divisors (see below), whose sum is σ = 1513807800. Its totient is φ = 1362426984.

The previous prime is 1438117379. The next prime is 1438117427. The reversal of 1438117391 is 1937118341.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1438117391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1438117321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37845176 + ... + 37845213.

It is an arithmetic number, because the mean of its divisors is an integer number (378451950).

Almost surely, 2^1438117391 is an apocalyptic number.

1438117391 is a deficient number, since it is larger than the sum of its proper divisors (75690409).

1438117391 is an equidigital number, since it uses as much as digits as its factorization.

1438117391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75690408.

The product of its digits is 18144, while the sum is 38.

The square root of 1438117391 is about 37922.5182576263. The cubic root of 1438117391 is about 1128.7509081284.

The spelling of 1438117391 in words is "one billion, four hundred thirty-eight million, one hundred seventeen thousand, three hundred ninety-one".