66534644 has 24 divisors (see below), whose sum is σ = 127813728. Its totient is φ = 30054240.

The previous prime is 66534593. The next prime is 66534647. The reversal of 66534644 is 44643566.

It is a happy number.

It is a super-3 number, since 3×66534644³ (a number of 24 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66534598 and 66534607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66534647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2534 + ... + 11810.

It is an arithmetic number, because the mean of its divisors is an integer number (5325572).

Almost surely, 2^66534644 is an apocalyptic number.

It is an amenable number.

66534644 is a deficient number, since it is larger than the sum of its proper divisors (61279084).

66534644 is a wasteful number, since it uses less digits than its factorization.

66534644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9455 (or 9453 counting only the distinct ones).

The product of its digits is 207360, while the sum is 38.

The square root of 66534644 is about 8156.8770984979. The cubic root of 66534644 is about 405.2122933135.

The spelling of 66534644 in words is "sixty-six million, five hundred thirty-four thousand, six hundred forty-four".