661608042 has 8 divisors (see below), whose sum is σ = 1323216096. Its totient is φ = 220536012.

The previous prime is 661608029. The next prime is 661608061. The reversal of 661608042 is 240806166.

It is a happy number.

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

661608042 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 661607994 and 661608012.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55133998 + ... + 55134009.

It is an arithmetic number, because the mean of its divisors is an integer number (165402012).

Almost surely, 2^661608042 is an apocalyptic number.

661608042 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

661608042 is a wasteful number, since it uses less digits than its factorization.

661608042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110268012.

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 661608042 is about 25721.7425926005. The cubic root of 661608042 is about 871.3652945518.

The spelling of 661608042 in words is "six hundred sixty-one million, six hundred eight thousand, forty-two".