891123408 has 540 divisors, whose sum is σ = 3385006560. Its totient is φ = 217147392.

The previous prime is 891123407. The next prime is 891123421. The reversal of 891123408 is 804321198.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (891123403) by changing a digit.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 38744485 + ... + 38744507.

Almost surely, 2^891123408 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 891123408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1692503280).

891123408 is an abundant number, since it is smaller than the sum of its proper divisors (2493883152).

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

891123408 is a wasteful number, since it uses less digits than its factorization.

891123408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 891123408 is about 29851.6902034039. The cubic root of 891123408 is about 962.3047229183.

The spelling of 891123408 in words is "eight hundred ninety-one million, one hundred twenty-three thousand, four hundred eight".