1285638 has 24 divisors (see below), whose sum is σ = 2654232. Its totient is φ = 415104.

The previous prime is 1285633. The next prime is 1285649. The reversal of 1285638 is 8365821.

It is a happy number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1285599 and 1285608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1285633) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13206 + ... + 13302.

It is an arithmetic number, because the mean of its divisors is an integer number (110593).

2^1285638 is an apocalyptic number.

1285638 is an abundant number, since it is smaller than the sum of its proper divisors (1368594).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1285638 is an equidigital number, since it uses as much as digits as its factorization.

1285638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196 (or 149 counting only the distinct ones).

The product of its digits is 11520, while the sum is 33.

The square root of 1285638 is about 1133.8597796906. The cubic root of 1285638 is about 108.7358866610.

The spelling of 1285638 in words is "one million, two hundred eighty-five thousand, six hundred thirty-eight".