1390643 has 2 divisors, whose sum is σ = 1390644. Its totient is φ = 1390642.

The previous prime is 1390639. The next prime is 1390681. The reversal of 1390643 is 3460931.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1390643 - 2² = 1390639 is a prime.

It is not a weakly prime, because it can be changed into another prime (1390633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 695321 + 695322.

It is an arithmetic number, because the mean of its divisors is an integer number (695322).

2^1390643 is an apocalyptic number.

1390643 is a deficient number, since it is larger than the sum of its proper divisors (1).

1390643 is an equidigital number, since it uses as much as digits as its factorization.

1390643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 26.

The square root of 1390643 is about 1179.2552734671. The cubic root of 1390643 is about 111.6191089780.

The spelling of 1390643 in words is "one million, three hundred ninety thousand, six hundred forty-three".