661363505 has 32 divisors (see below), whose sum is σ = 914457600. Its totient is φ = 454463680.

The previous prime is 661363489. The next prime is 661363519. The reversal of 661363505 is 505363166.

It is not a de Polignac number, because 661363505 - 2⁴ = 661363489 is a prime.

It is an unprimeable number.

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, 101846 + ... + 108144.

It is an arithmetic number, because the mean of its divisors is an integer number (28576800).

Almost surely, 2^661363505 is an apocalyptic number.

It is an amenable number.

661363505 is a deficient number, since it is larger than the sum of its proper divisors (253094095).

661363505 is a wasteful number, since it uses less digits than its factorization.

661363505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6421.

The product of its (nonzero) digits is 48600, while the sum is 35.

The square root of 661363505 is about 25716.9886456405. The cubic root of 661363505 is about 871.2579261911.

The spelling of 661363505 in words is "six hundred sixty-one million, three hundred sixty-three thousand, five hundred five".