661361423 has 4 divisors (see below), whose sum is σ = 668179680. Its totient is φ = 654543168.

The previous prime is 661361411. The next prime is 661361431. The reversal of 661361423 is 324163166.

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 661361423 - 2⁶ = 661361359 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 661361423.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661361483) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3408983 + ... + 3409176.

It is an arithmetic number, because the mean of its divisors is an integer number (167044920).

Almost surely, 2^661361423 is an apocalyptic number.

661361423 is a deficient number, since it is larger than the sum of its proper divisors (6818257).

661361423 is an equidigital number, since it uses as much as digits as its factorization.

661361423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6818256.

The product of its digits is 15552, while the sum is 32.

The square root of 661361423 is about 25716.9481665302. The cubic root of 661361423 is about 871.2570119380.

The spelling of 661361423 in words is "six hundred sixty-one million, three hundred sixty-one thousand, four hundred twenty-three".