1438539491 has 2 divisors, whose sum is σ = 1438539492. Its totient is φ = 1438539490.

The previous prime is 1438539467. The next prime is 1438539493. The reversal of 1438539491 is 1949358341.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1438539491 is a prime.

It is a Sophie Germain prime.

Together with 1438539493, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1438539493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 719269745 + 719269746.

It is an arithmetic number, because the mean of its divisors is an integer number (719269746).

Almost surely, 2^1438539491 is an apocalyptic number.

1438539491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1438539491 is an equidigital number, since it uses as much as digits as its factorization.

1438539491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 466560, while the sum is 47.

The square root of 1438539491 is about 37928.0831442877. The cubic root of 1438539491 is about 1128.8613300720.

The spelling of 1438539491 in words is "one billion, four hundred thirty-eight million, five hundred thirty-nine thousand, four hundred ninety-one".