1671638 has 4 divisors (see below), whose sum is σ = 2507460. Its totient is φ = 835818.

The previous prime is 1671629. The next prime is 1671641. The reversal of 1671638 is 8361761.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 417908 + ... + 417911.

It is an arithmetic number, because the mean of its divisors is an integer number (626865).

2^1671638 is an apocalyptic number.

1671638 is a deficient number, since it is larger than the sum of its proper divisors (835822).

1671638 is an equidigital number, since it uses as much as digits as its factorization.

1671638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 835821.

The product of its digits is 6048, while the sum is 32.

The square root of 1671638 is about 1292.9184042313. The cubic root of 1671638 is about 118.6808764843.

The spelling of 1671638 in words is "one million, six hundred seventy-one thousand, six hundred thirty-eight".