1390646 has 4 divisors (see below), whose sum is σ = 2085972. Its totient is φ = 695322.

The previous prime is 1390643. The next prime is 1390681. The reversal of 1390646 is 6460931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6460931 = 19 ⋅340049.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1390643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 347660 + ... + 347663.

It is an arithmetic number, because the mean of its divisors is an integer number (521493).

2^1390646 is an apocalyptic number.

1390646 is a deficient number, since it is larger than the sum of its proper divisors (695326).

1390646 is an equidigital number, since it uses as much as digits as its factorization.

1390646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 695325.

The product of its (nonzero) digits is 3888, while the sum is 29.

The square root of 1390646 is about 1179.2565454557. The cubic root of 1390646 is about 111.6191892423.

The spelling of 1390646 in words is "one million, three hundred ninety thousand, six hundred forty-six".