661309611 has 8 divisors (see below), whose sum is σ = 928153920. Its totient is φ = 417669192.

The previous prime is 661309603. The next prime is 661309613. The reversal of 661309611 is 116903166.

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

It is not a de Polignac number, because 661309611 - 2³ = 661309603 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661309613) 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, 5800905 + ... + 5801018.

It is an arithmetic number, because the mean of its divisors is an integer number (116019240).

Almost surely, 2^661309611 is an apocalyptic number.

661309611 is a deficient number, since it is larger than the sum of its proper divisors (266844309).

661309611 is a wasteful number, since it uses less digits than its factorization.

661309611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11601945.

The product of its (nonzero) digits is 5832, while the sum is 33.

The square root of 661309611 is about 25715.9407955455. The cubic root of 661309611 is about 871.2342595036.

The spelling of 661309611 in words is "six hundred sixty-one million, three hundred nine thousand, six hundred eleven".