1639481 has 2 divisors, whose sum is σ = 1639482. Its totient is φ = 1639480.

The previous prime is 1639471. The next prime is 1639493. The reversal of 1639481 is 1849361.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1229881 + 409600 = 1109^2 + 640^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1639481 is a prime.

It is a super-2 number, since 2×1639481² = 5375795898722, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1639471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 819740 + 819741.

It is an arithmetic number, because the mean of its divisors is an integer number (819741).

2^1639481 is an apocalyptic number.

It is an amenable number.

1639481 is a deficient number, since it is larger than the sum of its proper divisors (1).

1639481 is an equidigital number, since it uses as much as digits as its factorization.

1639481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 32.

The square root of 1639481 is about 1280.4221959963. The cubic root of 1639481 is about 117.9149295874.

The spelling of 1639481 in words is "one million, six hundred thirty-nine thousand, four hundred eighty-one".