661168997 has 4 divisors (see below), whose sum is σ = 661375500. Its totient is φ = 660962496.

The previous prime is 661168967. The next prime is 661169027. The reversal of 661168997 is 799861166.

661168997 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is an interprime number because it is at equal distance from previous prime (661168967) and next prime (661169027).

It can be written as a sum of positive squares in 2 ways, for example, as 335402596 + 325766401 = 18314^2 + 18049^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661168997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661168967) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 98372 + ... + 104877.

It is an arithmetic number, because the mean of its divisors is an integer number (165343875).

Almost surely, 2^661168997 is an apocalyptic number.

It is an amenable number.

661168997 is a deficient number, since it is larger than the sum of its proper divisors (206503).

661168997 is a wasteful number, since it uses less digits than its factorization.

661168997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206502.

The product of its digits is 979776, while the sum is 53.

The square root of 661168997 is about 25713.2066650583. The cubic root of 661168997 is about 871.1725050616.

The spelling of 661168997 in words is "six hundred sixty-one million, one hundred sixty-eight thousand, nine hundred ninety-seven".