856145521 has 8 divisors (see below), whose sum is σ = 1067402304. Its totient is φ = 667126320.

The previous prime is 856145503. The next prime is 856145527. The reversal of 856145521 is 125541658.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 856145521 - 2⁵ = 856145489 is a prime.

It is a super-2 number, since 2×856145521² = 1465970306256722882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (856145527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5559310 + ... + 5559463.

It is an arithmetic number, because the mean of its divisors is an integer number (133425288).

Almost surely, 2^856145521 is an apocalyptic number.

It is an amenable number.

856145521 is a deficient number, since it is larger than the sum of its proper divisors (211256783).

856145521 is a wasteful number, since it uses less digits than its factorization.

856145521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11118791.

The product of its digits is 48000, while the sum is 37.

The square root of 856145521 is about 29259.9644736626. The cubic root of 856145521 is about 949.5456815656.

It can be divided in two parts, 8561455 and 21, that added together give a square (8561476 = 2926²).

The spelling of 856145521 in words is "eight hundred fifty-six million, one hundred forty-five thousand, five hundred twenty-one".