821238220874 has 4 divisors (see below), whose sum is σ = 1231857331314. Its totient is φ = 410619110436.

The previous prime is 821238220849. The next prime is 821238220877. The reversal of 821238220874 is 478022832128.

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., 638872497025 + 182365723849 = 799295^2 + 427043^2 .

It is not an unprimeable number, because it can be changed into a prime (821238220877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 205309555217 + ... + 205309555220.

Almost surely, 2^821238220874 is an apocalyptic number.

821238220874 is a deficient number, since it is larger than the sum of its proper divisors (410619110440).

821238220874 is a wasteful number, since it uses less digits than its factorization.

821238220874 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410619110439.

The product of its (nonzero) digits is 688128, while the sum is 47.

The spelling of 821238220874 in words is "eight hundred twenty-one billion, two hundred thirty-eight million, two hundred twenty thousand, eight hundred seventy-four".