661603228 has 72 divisors (see below), whose sum is σ = 1377761616. Its totient is φ = 275558400.

The previous prime is 661603207. The next prime is 661603231. The reversal of 661603228 is 822306166.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 661603193 and 661603202.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 1434918 + ... + 1435378.

It is an arithmetic number, because the mean of its divisors is an integer number (19135578).

Almost surely, 2^661603228 is an apocalyptic number.

It is an amenable number.

661603228 is an abundant number, since it is smaller than the sum of its proper divisors (716158388).

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

661603228 is a wasteful number, since it uses less digits than its factorization.

661603228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 695 (or 680 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 661603228 is about 25721.6490140115. The cubic root of 661603228 is about 871.3631811340.

The spelling of 661603228 in words is "six hundred sixty-one million, six hundred three thousand, two hundred twenty-eight".