1653643 has 2 divisors, whose sum is σ = 1653644. Its totient is φ = 1653642.

The previous prime is 1653623. The next prime is 1653671. The reversal of 1653643 is 3463561.

It is an a-pointer prime, because the next prime (1653671) can be obtained adding 1653643 to its sum of digits (28).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1653643 - 2⁵ = 1653611 is a prime.

It is not a weakly prime, because it can be changed into another prime (1653623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 826821 + 826822.

It is an arithmetic number, because the mean of its divisors is an integer number (826822).

2^1653643 is an apocalyptic number.

1653643 is a deficient number, since it is larger than the sum of its proper divisors (1).

1653643 is an equidigital number, since it uses as much as digits as its factorization.

1653643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6480, while the sum is 28.

The square root of 1653643 is about 1285.9405118434. The cubic root of 1653643 is about 118.2534769466.

The spelling of 1653643 in words is "one million, six hundred fifty-three thousand, six hundred forty-three".