291386487666 has 16 divisors (see below), whose sum is σ = 582788786688. Its totient is φ = 97126194000.

The previous prime is 291386487611. The next prime is 291386487671. The reversal of 291386487666 is 666784683192.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 291386487597 and 291386487606.

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, 412125 + ... + 867536.

It is an arithmetic number, because the mean of its divisors is an integer number (36424299168).

Almost surely, 2^291386487666 is an apocalyptic number.

291386487666 is an abundant number, since it is smaller than the sum of its proper divisors (291402299022).

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

291386487666 is a wasteful number, since it uses less digits than its factorization.

291386487666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1317617.

The product of its digits is 125411328, while the sum is 66.

The spelling of 291386487666 in words is "two hundred ninety-one billion, three hundred eighty-six million, four hundred eighty-seven thousand, six hundred sixty-six".