891979506 has 128 divisors (see below), whose sum is σ = 2281478400. Its totient is φ = 255790080.

The previous prime is 891979483. The next prime is 891979513. The reversal of 891979506 is 605979198.

891979506 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 912490 + ... + 913466.

It is an arithmetic number, because the mean of its divisors is an integer number (17824050).

Almost surely, 2^891979506 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 891979506, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1140739200).

891979506 is an abundant number, since it is smaller than the sum of its proper divisors (1389498894).

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

891979506 is a wasteful number, since it uses less digits than its factorization.

891979506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1081 (or 1075 counting only the distinct ones).

The product of its (nonzero) digits is 1224720, while the sum is 54.

The square root of 891979506 is about 29866.0259492287. The cubic root of 891979506 is about 962.6127848045.

The spelling of 891979506 in words is "eight hundred ninety-one million, nine hundred seventy-nine thousand, five hundred six".