821406971 has 8 divisors (see below), whose sum is σ = 1024091904. Its totient is φ = 640057320.

The previous prime is 821406967. The next prime is 821406977. The reversal of 821406971 is 179604128.

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

It is not a de Polignac number, because 821406971 - 2² = 821406967 is a prime.

It is not an unprimeable number, because it can be changed into a prime (821406977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5333735 + ... + 5333888.

It is an arithmetic number, because the mean of its divisors is an integer number (128011488).

Almost surely, 2^821406971 is an apocalyptic number.

821406971 is a deficient number, since it is larger than the sum of its proper divisors (202684933).

821406971 is a wasteful number, since it uses less digits than its factorization.

821406971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10667641.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 821406971 is about 28660.1983768431. The cubic root of 821406971 is about 936.5251861102.

The spelling of 821406971 in words is "eight hundred twenty-one million, four hundred six thousand, nine hundred seventy-one".