661394299 has 4 divisors (see below), whose sum is σ = 700299864. Its totient is φ = 622488736.

The previous prime is 661394297. The next prime is 661394339. The reversal of 661394299 is 992493166.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 661394299 - 2¹ = 661394297 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661394291) 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, 19452757 + ... + 19452790.

It is an arithmetic number, because the mean of its divisors is an integer number (175074966).

Almost surely, 2^661394299 is an apocalyptic number.

661394299 is a deficient number, since it is larger than the sum of its proper divisors (38905565).

661394299 is a wasteful number, since it uses less digits than its factorization.

661394299 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38905564.

The product of its digits is 629856, while the sum is 49.

The square root of 661394299 is about 25717.5873479609. The cubic root of 661394299 is about 871.2714483061.

The spelling of 661394299 in words is "six hundred sixty-one million, three hundred ninety-four thousand, two hundred ninety-nine".