1663066561 has 16 divisors (see below), whose sum is σ = 1892499840. Its totient is φ = 1448755200.

The previous prime is 1663066507. The next prime is 1663066609. The reversal of 1663066561 is 1656603661.

It is a cyclic number.

It is not a de Polignac number, because 1663066561 - 2¹⁵ = 1663033793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1663066061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52161 + ... + 77761.

It is an arithmetic number, because the mean of its divisors is an integer number (118281240).

Almost surely, 2^1663066561 is an apocalyptic number.

It is an amenable number.

1663066561 is a deficient number, since it is larger than the sum of its proper divisors (229433279).

1663066561 is a wasteful number, since it uses less digits than its factorization.

1663066561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25896.

The product of its (nonzero) digits is 116640, while the sum is 40.

The square root of 1663066561 is about 40780.7131006803. The cubic root of 1663066561 is about 1184.7768066413.

The spelling of 1663066561 in words is "one billion, six hundred sixty-three million, sixty-six thousand, five hundred sixty-one".