66664161536 has 72 divisors (see below), whose sum is σ = 152639902464. Its totient is φ = 28464721920.

The previous prime is 66664161461. The next prime is 66664161559. The reversal of 66664161536 is 63516146666.

It is a super-2 number, since 2×66664161536² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 416996 + ... + 554268.

Almost surely, 2^66664161536 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66664161536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76319951232).

66664161536 is an abundant number, since it is smaller than the sum of its proper divisors (85975740928).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66664161536 is a wasteful number, since it uses less digits than its factorization.

66664161536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137567 (or 137553 counting only the distinct ones).

The product of its digits is 2799360, while the sum is 50.

The spelling of 66664161536 in words is "sixty-six billion, six hundred sixty-four million, one hundred sixty-one thousand, five hundred thirty-six".