1638473 has 2 divisors, whose sum is σ = 1638474. Its totient is φ = 1638472.

The previous prime is 1638463. The next prime is 1638487. The reversal of 1638473 is 3748361.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1630729 + 7744 = 1277^2 + 88^2 .

It is an emirp because it is prime and its reverse (3748361) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1638473 is a prime.

It is not a weakly prime, because it can be changed into another prime (1638463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 819236 + 819237.

It is an arithmetic number, because the mean of its divisors is an integer number (819237).

2^1638473 is an apocalyptic number.

It is an amenable number.

1638473 is a deficient number, since it is larger than the sum of its proper divisors (1).

1638473 is an equidigital number, since it uses as much as digits as its factorization.

1638473 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 32.

The square root of 1638473 is about 1280.0285153074. The cubic root of 1638473 is about 117.8907588048.

The spelling of 1638473 in words is "one million, six hundred thirty-eight thousand, four hundred seventy-three".