661042660 has 24 divisors (see below), whose sum is σ = 1407744576. Its totient is φ = 260692320.

The previous prime is 661042651. The next prime is 661042663. The reversal of 661042660 is 66240166.

It is not an unprimeable number, because it can be changed into a prime (661042663) 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 7 ways as a sum of consecutive naturals, for example, 231342 + ... + 234181.

It is an arithmetic number, because the mean of its divisors is an integer number (58656024).

Almost surely, 2^661042660 is an apocalyptic number.

It is an amenable number.

661042660 is an abundant number, since it is smaller than the sum of its proper divisors (746701916).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661042660 is a wasteful number, since it uses less digits than its factorization.

661042660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 465603 (or 465601 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 31.

The square root of 661042660 is about 25710.7498918254. The cubic root of 661042660 is about 871.1170132825.

The spelling of 661042660 in words is "six hundred sixty-one million, forty-two thousand, six hundred sixty".