664845687442 has 8 divisors (see below), whose sum is σ = 997398593100. Its totient is φ = 332379489744.

The previous prime is 664845687437. The next prime is 664845687463. The reversal of 664845687442 is 244786548466.

It can be written as a sum of positive squares in 2 ways, for example, as 664027784641 + 817902801 = 814879^2 + 28599^2 .

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

It is a super-2 number, since 2×664845687442² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 21657817 + ... + 21688492.

Almost surely, 2^664845687442 is an apocalyptic number.

664845687442 is a deficient number, since it is larger than the sum of its proper divisors (332552905658).

664845687442 is a wasteful number, since it uses less digits than its factorization.

664845687442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43353980.

The product of its digits is 247726080, while the sum is 64.

The spelling of 664845687442 in words is "six hundred sixty-four billion, eight hundred forty-five million, six hundred eighty-seven thousand, four hundred forty-two".