66910644 has 24 divisors (see below), whose sum is σ = 173472320. Its totient is φ = 22303512.

The previous prime is 66910643. The next prime is 66910687. The reversal of 66910644 is 44601966.

66910644 is a `hidden beast` number, since 6 + 6 + 9 + 1 + 0 + 644 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 66910599 and 66910608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66910643) 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, 309664 + ... + 309879.

Almost surely, 2^66910644 is an apocalyptic number.

It is an amenable number.

66910644 is an abundant number, since it is smaller than the sum of its proper divisors (106561676).

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

66910644 is a wasteful number, since it uses less digits than its factorization.

66910644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 619556 (or 619548 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 66910644 is about 8179.8926643325. The cubic root of 66910644 is about 405.9741706654.

The spelling of 66910644 in words is "sixty-six million, nine hundred ten thousand, six hundred forty-four".