661009105 has 8 divisors (see below), whose sum is σ = 793464192. Its totient is φ = 528638448.

The previous prime is 661009103. The next prime is 661009123. The reversal of 661009105 is 501900166.

661009105 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 661009105 - 2¹ = 661009103 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661009103) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2367 + ... + 36436.

It is an arithmetic number, because the mean of its divisors is an integer number (99183024).

Almost surely, 2^661009105 is an apocalyptic number.

It is an amenable number.

661009105 is a deficient number, since it is larger than the sum of its proper divisors (132455087).

661009105 is a wasteful number, since it uses less digits than its factorization.

661009105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42215.

The product of its (nonzero) digits is 1620, while the sum is 28.

The square root of 661009105 is about 25710.0973354828. The cubic root of 661009105 is about 871.1022735248.

The spelling of 661009105 in words is "six hundred sixty-one million, nine thousand, one hundred five".