661788843 has 8 divisors (see below), whose sum is σ = 882504000. Its totient is φ = 441133128.

The previous prime is 661788839. The next prime is 661788847. The reversal of 661788843 is 348887166.

661788843 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (661788839) and next prime (661788847).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 661788843 - 2² = 661788839 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661788847) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35608 + ... + 50906.

It is an arithmetic number, because the mean of its divisors is an integer number (110313000).

Almost surely, 2^661788843 is an apocalyptic number.

661788843 is a deficient number, since it is larger than the sum of its proper divisors (220715157).

661788843 is a wasteful number, since it uses less digits than its factorization.

661788843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29721.

The product of its digits is 1548288, while the sum is 51.

The square root of 661788843 is about 25725.2569083382. The cubic root of 661788843 is about 871.4446614669. Note that the first 3 decimals are identical.

The spelling of 661788843 in words is "six hundred sixty-one million, seven hundred eighty-eight thousand, eight hundred forty-three".