668019842 has 24 divisors (see below), whose sum is σ = 1166986764. Its totient is φ = 285960192.

The previous prime is 668019839. The next prime is 668019893. The reversal of 668019842 is 248910866.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 661055521 + 6964321 = 25711^2 + 2639^2 .

It is a junction number, because it is equal to n+sod(n) for n = 668019793 and 668019802.

It is an unprimeable number.

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 in 11 ways as a sum of consecutive naturals, for example, 92258 + ... + 99234.

Almost surely, 2^668019842 is an apocalyptic number.

668019842 is a deficient number, since it is larger than the sum of its proper divisors (498966922).

668019842 is a wasteful number, since it uses less digits than its factorization.

668019842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7970 (or 7963 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 44.

The square root of 668019842 is about 25846.0798188042. The cubic root of 668019842 is about 874.1711190552.

The spelling of 668019842 in words is "six hundred sixty-eight million, nineteen thousand, eight hundred forty-two".