891523 has 2 divisors, whose sum is σ = 891524. Its totient is φ = 891522.

The previous prime is 891521. The next prime is 891551. The reversal of 891523 is 325198.

891523 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an a-pointer prime, because the next prime (891551) can be obtained adding 891523 to its sum of digits (28).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 891523 - 2¹ = 891521 is a prime.

Together with 891521, it forms a pair of twin primes.

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 891491 and 891500.

It is not a weakly prime, because it can be changed into another prime (891521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 445761 + 445762.

It is an arithmetic number, because the mean of its divisors is an integer number (445762).

2⁸⁹¹⁵²³ is an apocalyptic number.

891523 is a deficient number, since it is larger than the sum of its proper divisors (1).

891523 is an equidigital number, since it uses as much as digits as its factorization.

891523 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2160, while the sum is 28.

The square root of 891523 is about 944.2049565640. The cubic root of 891523 is about 96.2448538318.

The spelling of 891523 in words is "eight hundred ninety-one thousand, five hundred twenty-three".