661200847 has 4 divisors (see below), whose sum is σ = 668630160. Its totient is φ = 653771536.

The previous prime is 661200821. The next prime is 661200863. The reversal of 661200847 is 748002166.

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 661200847 - 2⁷ = 661200719 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 (661200877) 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, 3714523 + ... + 3714700.

It is an arithmetic number, because the mean of its divisors is an integer number (167157540).

Almost surely, 2^661200847 is an apocalyptic number.

661200847 is a deficient number, since it is larger than the sum of its proper divisors (7429313).

661200847 is an equidigital number, since it uses as much as digits as its factorization.

661200847 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7429312.

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 661200847 is about 25713.8259891444. The cubic root of 661200847 is about 871.1864936176.

The spelling of 661200847 in words is "six hundred sixty-one million, two hundred thousand, eight hundred forty-seven".