661348799 has 4 divisors (see below), whose sum is σ = 684153960. Its totient is φ = 638543640.

The previous prime is 661348783. The next prime is 661348801. The reversal of 661348799 is 997843166.

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 661348799 - 2⁴ = 661348783 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 661348799.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661341799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11402537 + ... + 11402594.

It is an arithmetic number, because the mean of its divisors is an integer number (171038490).

Almost surely, 2^661348799 is an apocalyptic number.

661348799 is a deficient number, since it is larger than the sum of its proper divisors (22805161).

661348799 is a wasteful number, since it uses less digits than its factorization.

661348799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22805160.

The product of its digits is 1959552, while the sum is 53.

The square root of 661348799 is about 25716.7027241052. The cubic root of 661348799 is about 871.2514684141.

The spelling of 661348799 in words is "six hundred sixty-one million, three hundred forty-eight thousand, seven hundred ninety-nine".