1663537655 has 16 divisors (see below), whose sum is σ = 2219153664. Its totient is φ = 1188829440.

The previous prime is 1663537639. The next prime is 1663537697. The reversal of 1663537655 is 5567353661.

It is not a de Polignac number, because 1663537655 - 2⁴ = 1663537639 is a prime.

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 410774 + ... + 414803.

It is an arithmetic number, because the mean of its divisors is an integer number (138697104).

Almost surely, 2^1663537655 is an apocalyptic number.

1663537655 is a deficient number, since it is larger than the sum of its proper divisors (555616009).

1663537655 is a wasteful number, since it uses less digits than its factorization.

1663537655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 825626.

The product of its digits is 1701000, while the sum is 47.

The square root of 1663537655 is about 40786.4886328794. The cubic root of 1663537655 is about 1184.8886659750. Note that the first 3 decimals are identical.

The spelling of 1663537655 in words is "one billion, six hundred sixty-three million, five hundred thirty-seven thousand, six hundred fifty-five".