100505661 has 4 divisors (see below), whose sum is σ = 134007552. Its totient is φ = 67003772.

The previous prime is 100505659. The next prime is 100505729. The reversal of 100505661 is 166505001.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 100505661 - 2¹ = 100505659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100505651) 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 3 ways as a sum of consecutive naturals, for example, 16750941 + ... + 16750946.

It is an arithmetic number, because the mean of its divisors is an integer number (33501888).

Almost surely, 2^100505661 is an apocalyptic number.

It is an amenable number.

100505661 is a deficient number, since it is larger than the sum of its proper divisors (33501891).

100505661 is an equidigital number, since it uses as much as digits as its factorization.

100505661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33501890.

The product of its (nonzero) digits is 900, while the sum is 24.

The square root of 100505661 is about 10025.2511689234. The cubic root of 100505661 is about 464.9399251793.

The spelling of 100505661 in words is "one hundred million, five hundred five thousand, six hundred sixty-one".