891139680 has 72 divisors (see below), whose sum is σ = 3041019072. Its totient is φ = 237636864.

The previous prime is 891139663. The next prime is 891139687. The reversal of 891139680 is 86931198.

891139680 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (891139687) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 307984 + ... + 310863.

It is an arithmetic number, because the mean of its divisors is an integer number (42236376).

Almost surely, 2^891139680 is an apocalyptic number.

891139680 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

891139680 is an abundant number, since it is smaller than the sum of its proper divisors (2149879392).

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

891139680 is a wasteful number, since it uses less digits than its factorization.

891139680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 618868 (or 618857 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The square root of 891139680 is about 29851.9627495413. The cubic root of 891139680 is about 962.3105801419.

The spelling of 891139680 in words is "eight hundred ninety-one million, one hundred thirty-nine thousand, six hundred eighty".