1386639 has 40 divisors (see below), whose sum is σ = 2352240. Its totient is φ = 808704.

The previous prime is 1386631. The next prime is 1386643. The reversal of 1386639 is 9366831.

It is a happy number.

1386639 is a `hidden beast` number, since 13 + 8 + 6 + 639 = 666.

It is not a de Polignac number, because 1386639 - 2³ = 1386631 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1386631) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 26137 + ... + 26189.

It is an arithmetic number, because the mean of its divisors is an integer number (58806).

2^1386639 is an apocalyptic number.

1386639 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

1386639 is a deficient number, since it is larger than the sum of its proper divisors (965601).

1386639 is a wasteful number, since it uses less digits than its factorization.

1386639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101 (or 92 counting only the distinct ones).

The product of its digits is 23328, while the sum is 36.

The square root of 1386639 is about 1177.5563680776. The cubic root of 1386639 is about 111.5118797962.

It can be divided in two parts, 1386 and 639, that added together give a square (2025 = 45²).

The spelling of 1386639 in words is "one million, three hundred eighty-six thousand, six hundred thirty-nine".