1638487 has 2 divisors, whose sum is σ = 1638488. Its totient is φ = 1638486.

The previous prime is 1638473. The next prime is 1638547. The reversal of 1638487 is 7848361.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1638487 - 2¹⁵ = 1605719 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1632487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 819243 + 819244.

It is an arithmetic number, because the mean of its divisors is an integer number (819244).

2^1638487 is an apocalyptic number.

1638487 is a deficient number, since it is larger than the sum of its proper divisors (1).

1638487 is an equidigital number, since it uses as much as digits as its factorization.

1638487 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32256, while the sum is 37.

The square root of 1638487 is about 1280.0339839239. The cubic root of 1638487 is about 117.8910945780.

It can be divided in two parts, 16384 and 87, that added together give a triangular number (16471 = T₁₈₁).

The spelling of 1638487 in words is "one million, six hundred thirty-eight thousand, four hundred eighty-seven".