66646836 has 18 divisors (see below), whose sum is σ = 168468482. Its totient is φ = 22215600.

The previous prime is 66646829. The next prime is 66646897. The reversal of 66646836 is 63864666.

It can be written as a sum of positive squares in only one way, i.e., 63297936 + 3348900 = 7956^2 + 1830^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a junction number, because it is equal to n+sod(n) for n = 66646791 and 66646800.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 925615 + ... + 925686.

Almost surely, 2^66646836 is an apocalyptic number.

It is an amenable number.

66646836 is an abundant number, since it is smaller than the sum of its proper divisors (101821646).

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

66646836 is a wasteful number, since it uses less digits than its factorization.

66646836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1851311 (or 1851306 counting only the distinct ones).

The product of its digits is 746496, while the sum is 45.

The square root of 66646836 is about 8163.7513435920. The cubic root of 66646836 is about 405.4399243443.

The spelling of 66646836 in words is "sixty-six million, six hundred forty-six thousand, eight hundred thirty-six".