1375639 has 2 divisors, whose sum is σ = 1375640. Its totient is φ = 1375638.

The previous prime is 1375637. The next prime is 1375669. The reversal of 1375639 is 9365731.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1375639 - 2¹ = 1375637 is a prime.

Together with 1375637, it forms a pair of twin primes.

1375639 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1375637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 687819 + 687820.

It is an arithmetic number, because the mean of its divisors is an integer number (687820).

2^1375639 is an apocalyptic number.

1375639 is a deficient number, since it is larger than the sum of its proper divisors (1).

1375639 is an equidigital number, since it uses as much as digits as its factorization.

1375639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17010, while the sum is 34.

The square root of 1375639 is about 1172.8763788226. The cubic root of 1375639 is about 111.2162275974.

It can be divided in two parts, 137 and 5639, that added together give a square (5776 = 76²).

The spelling of 1375639 in words is "one million, three hundred seventy-five thousand, six hundred thirty-nine".