1649639 has 2 divisors, whose sum is σ = 1649640. Its totient is φ = 1649638.

The previous prime is 1649621. The next prime is 1649647. The reversal of 1649639 is 9369461.

It is a strong prime.

It is an emirp because it is prime and its reverse (9369461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1649639 - 2¹² = 1645543 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1649689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 824819 + 824820.

It is an arithmetic number, because the mean of its divisors is an integer number (824820).

2^1649639 is an apocalyptic number.

1649639 is a deficient number, since it is larger than the sum of its proper divisors (1).

1649639 is an equidigital number, since it uses as much as digits as its factorization.

1649639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34992, while the sum is 38.

The square root of 1649639 is about 1284.3827311203. The cubic root of 1649639 is about 118.1579566134.

The spelling of 1649639 in words is "one million, six hundred forty-nine thousand, six hundred thirty-nine".