661956341 has 4 divisors (see below), whose sum is σ = 673176000. Its totient is φ = 650736684.

The previous prime is 661956271. The next prime is 661956391. The reversal of 661956341 is 143659166.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661956341 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 (661956391) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5609741 + ... + 5609858.

It is an arithmetic number, because the mean of its divisors is an integer number (168294000).

Almost surely, 2^661956341 is an apocalyptic number.

It is an amenable number.

661956341 is a deficient number, since it is larger than the sum of its proper divisors (11219659).

661956341 is a wasteful number, since it uses less digits than its factorization.

661956341 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11219658.

The product of its digits is 116640, while the sum is 41.

The square root of 661956341 is about 25728.5122189372. The cubic root of 661956341 is about 871.5181758145.

The spelling of 661956341 in words is "six hundred sixty-one million, nine hundred fifty-six thousand, three hundred forty-one".