661005099 has 12 divisors (see below), whose sum is σ = 955014112. Its totient is φ = 440564400.

The previous prime is 661005097. The next prime is 661005109. The reversal of 661005099 is 990500166.

661005099 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 661005099 - 2¹ = 661005097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661005097) 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, 55614 + ... + 66444.

Almost surely, 2^661005099 is an apocalyptic number.

661005099 is a deficient number, since it is larger than the sum of its proper divisors (294009013).

661005099 is a wasteful number, since it uses less digits than its factorization.

661005099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17618 (or 17615 counting only the distinct ones).

The product of its (nonzero) digits is 14580, while the sum is 36.

The square root of 661005099 is about 25710.0194282307. The cubic root of 661005099 is about 871.1005137695.

The spelling of 661005099 in words is "six hundred sixty-one million, five thousand, ninety-nine".