661212343 has 4 divisors (see below), whose sum is σ = 721322568. Its totient is φ = 601102120.

The previous prime is 661212341. The next prime is 661212379. The reversal of 661212343 is 343212166.

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 661212343 - 2¹ = 661212341 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 (661212341) 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, 30055096 + ... + 30055117.

It is an arithmetic number, because the mean of its divisors is an integer number (180330642).

Almost surely, 2^661212343 is an apocalyptic number.

661212343 is a deficient number, since it is larger than the sum of its proper divisors (60110225).

661212343 is a wasteful number, since it uses less digits than its factorization.

661212343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60110224.

The product of its digits is 5184, while the sum is 28.

The square root of 661212343 is about 25714.0495255026. The cubic root of 661212343 is about 871.1915425635.

It can be divided in two parts, 6612123 and 43, that added together give a palindrome (6612166).

The spelling of 661212343 in words is "six hundred sixty-one million, two hundred twelve thousand, three hundred forty-three".