821284641 has 12 divisors (see below), whose sum is σ = 1186757520. Its totient is φ = 547311960.

The previous prime is 821284609. The next prime is 821284687. The reversal of 821284641 is 146482128.

821284641 is a `hidden beast` number, since 8 + 2 + 1 + 2 + 8 + 4 + 641 = 666.

It is not a de Polignac number, because 821284641 - 2⁵ = 821284609 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 821284596 and 821284605.

It is not an unprimeable number, because it can be changed into a prime (821284241) 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, 9186 + ... + 41556.

It is an arithmetic number, because the mean of its divisors is an integer number (98896460).

Almost surely, 2^821284641 is an apocalyptic number.

It is an amenable number.

821284641 is a deficient number, since it is larger than the sum of its proper divisors (365472879).

821284641 is a wasteful number, since it uses less digits than its factorization.

821284641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35196 (or 35193 counting only the distinct ones).

The product of its digits is 24576, while the sum is 36.

The square root of 821284641 is about 28658.0641530443. The cubic root of 821284641 is about 936.4786923835.

The spelling of 821284641 in words is "eight hundred twenty-one million, two hundred eighty-four thousand, six hundred forty-one".