891271836 has 480 divisors, whose sum is σ = 3172252160. Its totient is φ = 211631616.

The previous prime is 891271813. The next prime is 891271837. The reversal of 891271836 is 638172198.

It is a junction number, because it is equal to n+sod(n) for n = 891271791 and 891271800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (891271837) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 20727231 + ... + 20727273.

Almost surely, 2^891271836 is an apocalyptic number.

891271836 is a gapful number since it is divisible by the number (86) 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 891271836, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1586126080).

891271836 is an abundant number, since it is smaller than the sum of its proper divisors (2280980324).

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

891271836 is a wasteful number, since it uses less digits than its factorization.

891271836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135 (or 124 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 891271836 is about 29854.1761902753. The cubic root of 891271836 is about 962.3581480049.

The spelling of 891271836 in words is "eight hundred ninety-one million, two hundred seventy-one thousand, eight hundred thirty-six".