661559141 has 8 divisors (see below), whose sum is σ = 664955544. Its totient is φ = 658172160.

The previous prime is 661559137. The next prime is 661559147. The reversal of 661559141 is 141955166.

It can be written as a sum of positive squares in 4 ways, for example, as 264712900 + 396846241 = 16270^2 + 19921^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 661559141 - 2² = 661559137 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 661559095 and 661559104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661559147) 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, 168521 + ... + 172401.

It is an arithmetic number, because the mean of its divisors is an integer number (83119443).

Almost surely, 2^661559141 is an apocalyptic number.

It is an amenable number.

661559141 is a deficient number, since it is larger than the sum of its proper divisors (3396403).

661559141 is a wasteful number, since it uses less digits than its factorization.

661559141 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4711.

The product of its digits is 32400, while the sum is 38.

The square root of 661559141 is about 25720.7919979148. The cubic root of 661559141 is about 871.3438258063.

It can be divided in two parts, 6615 and 59141, that added together give a palindrome (65756).

The spelling of 661559141 in words is "six hundred sixty-one million, five hundred fifty-nine thousand, one hundred forty-one".