661218486 has 16 divisors (see below), whose sum is σ = 1325041200. Its totient is φ = 219972128.

The previous prime is 661218461. The next prime is 661218497. The reversal of 661218486 is 684812166.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 105201 + ... + 111308.

It is an arithmetic number, because the mean of its divisors is an integer number (82815075).

Almost surely, 2^661218486 is an apocalyptic number.

661218486 is an abundant number, since it is smaller than the sum of its proper divisors (663822714).

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

661218486 is a wasteful number, since it uses less digits than its factorization.

661218486 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 217023.

The product of its digits is 110592, while the sum is 42.

The square root of 661218486 is about 25714.1689735445. The cubic root of 661218486 is about 871.1942404931.

The spelling of 661218486 in words is "six hundred sixty-one million, two hundred eighteen thousand, four hundred eighty-six".