821347381874 has 4 divisors (see below), whose sum is σ = 1232021072814. Its totient is φ = 410673690936.

The previous prime is 821347381867. The next prime is 821347381903. The reversal of 821347381874 is 478183743128.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 752915437849 + 68431944025 = 867707^2 + 261595^2 .

It is a super-2 number, since 2×821347381874² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 205336845467 + ... + 205336845470.

Almost surely, 2^821347381874 is an apocalyptic number.

821347381874 is a deficient number, since it is larger than the sum of its proper divisors (410673690940).

821347381874 is a wasteful number, since it uses less digits than its factorization.

821347381874 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410673690939.

The product of its digits is 7225344, while the sum is 56.

The spelling of 821347381874 in words is "eight hundred twenty-one billion, three hundred forty-seven million, three hundred eighty-one thousand, eight hundred seventy-four".