661658798 has 8 divisors (see below), whose sum is σ = 1006467120. Its totient is φ = 326169760.

The previous prime is 661658791. The next prime is 661658801. The reversal of 661658798 is 897856166.

It is a happy number.

661658798 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661658791) 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, 2329643 + ... + 2329926.

It is an arithmetic number, because the mean of its divisors is an integer number (125808390).

Almost surely, 2^661658798 is an apocalyptic number.

661658798 is a deficient number, since it is larger than the sum of its proper divisors (344808322).

661658798 is a wasteful number, since it uses less digits than its factorization.

661658798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4659642.

The product of its digits is 4354560, while the sum is 56.

The square root of 661658798 is about 25722.7292097864. The cubic root of 661658798 is about 871.3875765693.

The spelling of 661658798 in words is "six hundred sixty-one million, six hundred fifty-eight thousand, seven hundred ninety-eight".