661218446 has 12 divisors (see below), whose sum is σ = 1153758888. Its totient is φ = 283379292.

The previous prime is 661218443. The next prime is 661218457. The reversal of 661218446 is 644812166.

661218446 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661218443) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3373466 + ... + 3373661.

It is an arithmetic number, because the mean of its divisors is an integer number (96146574).

Almost surely, 2^661218446 is an apocalyptic number.

661218446 is a deficient number, since it is larger than the sum of its proper divisors (492540442).

661218446 is a wasteful number, since it uses less digits than its factorization.

661218446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6747143 (or 6747136 counting only the distinct ones).

The product of its digits is 55296, while the sum is 38.

The square root of 661218446 is about 25714.1681957632. The cubic root of 661218446 is about 871.1942229257.

The spelling of 661218446 in words is "six hundred sixty-one million, two hundred eighteen thousand, four hundred forty-six".