891097538686 has 64 divisors (see below), whose sum is σ = 1399881787200. Its totient is φ = 424898166784.

The previous prime is 891097538659. The next prime is 891097538687. The reversal of 891097538686 is 686835790198.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (891097538687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1316244180 + ... + 1316244856.

It is an arithmetic number, because the mean of its divisors is an integer number (21873152925).

Almost surely, 2^891097538686 is an apocalyptic number.

891097538686 is a deficient number, since it is larger than the sum of its proper divisors (508784248514).

891097538686 is a wasteful number, since it uses less digits than its factorization.

891097538686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1581.

The product of its (nonzero) digits is 156764160, while the sum is 70.

The spelling of 891097538686 in words is "eight hundred ninety-one billion, ninety-seven million, five hundred thirty-eight thousand, six hundred eighty-six".