661335533163 has 12 divisors (see below), whose sum is σ = 959226184488. Its totient is φ = 439060933440.

The previous prime is 661335533161. The next prime is 661335533189. The reversal of 661335533163 is 361335533166.

661335533163 is a `hidden beast` number, since 6 + 6 + 1 + 3 + 3 + 553 + 31 + 63 = 666.

It is not a de Polignac number, because 661335533163 - 2¹ = 661335533161 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (661335533161) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 152449545 + ... + 152453882.

It is an arithmetic number, because the mean of its divisors is an integer number (79935515374).

Almost surely, 2^661335533163 is an apocalyptic number.

661335533163 is a deficient number, since it is larger than the sum of its proper divisors (297890651325).

661335533163 is a wasteful number, since it uses less digits than its factorization.

661335533163 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304903674 (or 304903671 counting only the distinct ones).

The product of its digits is 1312200, while the sum is 45.

The spelling of 661335533163 in words is "six hundred sixty-one billion, three hundred thirty-five million, five hundred thirty-three thousand, one hundred sixty-three".