661765602 has 8 divisors (see below), whose sum is σ = 1323531216. Its totient is φ = 220588532.

The previous prime is 661765583. The next prime is 661765607. The reversal of 661765602 is 206567166.

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

661765602 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (661765607) 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, 55147128 + ... + 55147139.

It is an arithmetic number, because the mean of its divisors is an integer number (165441402).

Almost surely, 2^661765602 is an apocalyptic number.

661765602 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.

661765602 is a wasteful number, since it uses less digits than its factorization.

661765602 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110294272.

The product of its (nonzero) digits is 90720, while the sum is 39.

The square root of 661765602 is about 25724.8051887667. The cubic root of 661765602 is about 871.4344600849.

The spelling of 661765602 in words is "six hundred sixty-one million, seven hundred sixty-five thousand, six hundred two".