661609052 has 12 divisors (see below), whose sum is σ = 1246878696. Its totient is φ = 305358000.

The previous prime is 661608977. The next prime is 661609057. The reversal of 661609052 is 250906166.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661609057) 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, 6361574 + ... + 6361677.

It is an arithmetic number, because the mean of its divisors is an integer number (103906558).

Almost surely, 2^661609052 is an apocalyptic number.

It is an amenable number.

661609052 is a deficient number, since it is larger than the sum of its proper divisors (585269644).

661609052 is a wasteful number, since it uses less digits than its factorization.

661609052 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12723268 (or 12723266 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 661609052 is about 25721.7622257885. The cubic root of 661609052 is about 871.3657379556.

The spelling of 661609052 in words is "six hundred sixty-one million, six hundred nine thousand, fifty-two".