661110143 has 2 divisors, whose sum is σ = 661110144. Its totient is φ = 661110142.

The previous prime is 661110031. The next prime is 661110167. The reversal of 661110143 is 341011166.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661110143 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661110343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330555071 + 330555072.

It is an arithmetic number, because the mean of its divisors is an integer number (330555072).

Almost surely, 2^661110143 is an apocalyptic number.

661110143 is a deficient number, since it is larger than the sum of its proper divisors (1).

661110143 is an equidigital number, since it uses as much as digits as its factorization.

661110143 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 661110143 is about 25712.0622082322. The cubic root of 661110143 is about 871.1466551360.

The spelling of 661110143 in words is "six hundred sixty-one million, one hundred ten thousand, one hundred forty-three".