664642239458 has 6 divisors (see below), whose sum is σ = 996965088609. Its totient is φ = 332320543256.

The previous prime is 664642239427. The next prime is 664642239461. The reversal of 664642239458 is 854932246466.

It can be written as a sum of positive squares in 2 ways, for example, as 524629321969 + 140012917489 = 724313^2 + 374183^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=576473.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 664642239397 and 664642239406.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 864710 + ... + 1441182.

Almost surely, 2^664642239458 is an apocalyptic number.

664642239458 is a deficient number, since it is larger than the sum of its proper divisors (332322849151).

664642239458 is an frugal number, since it uses more digits than its factorization.

664642239458 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1152948 (or 576475 counting only the distinct ones).

The product of its digits is 59719680, while the sum is 59.

The spelling of 664642239458 in words is "six hundred sixty-four billion, six hundred forty-two million, two hundred thirty-nine thousand, four hundred fifty-eight".