821916441 has 24 divisors (see below), whose sum is σ = 1199637504. Its totient is φ = 542233440.

The previous prime is 821916437. The next prime is 821916443. The reversal of 821916441 is 144619128.

821916441 is a `hidden beast` number, since 8 + 2 + 1 + 9 + 1 + 644 + 1 = 666.

It is not a de Polignac number, because 821916441 - 2² = 821916437 is a prime.

It is a super-2 number, since 2×821916441² = 1351093271972212962, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 821916396 and 821916405.

It is not an unprimeable number, because it can be changed into a prime (821916443) 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 23 ways as a sum of consecutive naturals, for example, 636006 + ... + 637296.

It is an arithmetic number, because the mean of its divisors is an integer number (49984896).

Almost surely, 2^821916441 is an apocalyptic number.

It is an amenable number.

821916441 is a deficient number, since it is larger than the sum of its proper divisors (377721063).

821916441 is a wasteful number, since it uses less digits than its factorization.

821916441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1981 (or 1978 counting only the distinct ones).

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

The square root of 821916441 is about 28669.0851092252. The cubic root of 821916441 is about 936.7187697588.

The spelling of 821916441 in words is "eight hundred twenty-one million, nine hundred sixteen thousand, four hundred forty-one".