891919687680 has 672 divisors, whose sum is σ = 3546192356928. Its totient is φ = 203135385600.

The previous prime is 891919687627. The next prime is 891919687741. The reversal of 891919687680 is 86786919198.

It is a tau number, because it is divible by the number of its divisors (672).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 891919687599 and 891919687608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1086381670 + ... + 1086382490.

Almost surely, 2^891919687680 is an apocalyptic number.

891919687680 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 891919687680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1773096178464).

891919687680 is an abundant number, since it is smaller than the sum of its proper divisors (2654272669248).

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

891919687680 is a wasteful number, since it uses less digits than its factorization.

891919687680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1286 (or 1259 counting only the distinct ones).

The product of its (nonzero) digits is 94058496, while the sum is 72.

The spelling of 891919687680 in words is "eight hundred ninety-one billion, nine hundred nineteen million, six hundred eighty-seven thousand, six hundred eighty".