1563641 has 4 divisors (see below), whose sum is σ = 1581300. Its totient is φ = 1545984.

The previous prime is 1563631. The next prime is 1563649. The reversal of 1563641 is 1463651.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 133225 + 1430416 = 365^2 + 1196^2 .

It is a cyclic number.

It is not a de Polignac number, because 1563641 - 2⁶ = 1563577 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1563641.

It is not an unprimeable number, because it can be changed into a prime (1563649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8696 + ... + 8873.

It is an arithmetic number, because the mean of its divisors is an integer number (395325).

2^1563641 is an apocalyptic number.

It is an amenable number.

1563641 is a deficient number, since it is larger than the sum of its proper divisors (17659).

1563641 is an equidigital number, since it uses as much as digits as its factorization.

1563641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17658.

The product of its digits is 2160, while the sum is 26.

The square root of 1563641 is about 1250.4563167100. The cubic root of 1563641 is about 116.0679595830.

The spelling of 1563641 in words is "one million, five hundred sixty-three thousand, six hundred forty-one".