817978022 has 4 divisors (see below), whose sum is σ = 1226967036. Its totient is φ = 408989010.

The previous prime is 817977961. The next prime is 817978027. The reversal of 817978022 is 220879718.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (817978027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 204494504 + ... + 204494507.

It is an arithmetic number, because the mean of its divisors is an integer number (306741759).

Almost surely, 2^817978022 is an apocalyptic number.

817978022 is a deficient number, since it is larger than the sum of its proper divisors (408989014).

817978022 is a wasteful number, since it uses less digits than its factorization.

817978022 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 408989013.

The product of its (nonzero) digits is 112896, while the sum is 44.

The square root of 817978022 is about 28600.3150681946. The cubic root of 817978022 is about 935.2201992170.

The spelling of 817978022 in words is "eight hundred seventeen million, nine hundred seventy-eight thousand, twenty-two".