1563396666 has 64 divisors (see below), whose sum is σ = 3529975680. Its totient is φ = 458357760.

The previous prime is 1563396661. The next prime is 1563396671. The reversal of 1563396666 is 6666933651.

It is an interprime number because it is at equal distance from previous prime (1563396661) and next prime (1563396671).

It is not an unprimeable number, because it can be changed into a prime (1563396661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 131830 + ... + 143198.

It is an arithmetic number, because the mean of its divisors is an integer number (55155870).

Almost surely, 2^1563396666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1563396666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1764987840).

1563396666 is an abundant number, since it is smaller than the sum of its proper divisors (1966579014).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1563396666 is a wasteful number, since it uses less digits than its factorization.

1563396666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11471.

The product of its digits is 3149280, while the sum is 51.

The square root of 1563396666 is about 39539.8111528115. The cubic root of 1563396666 is about 1160.6191368838.

The spelling of 1563396666 in words is "one billion, five hundred sixty-three million, three hundred ninety-six thousand, six hundred sixty-six".