66641628 has 12 divisors (see below), whose sum is σ = 155497160. Its totient is φ = 22213872.

The previous prime is 66641609. The next prime is 66641639. The reversal of 66641628 is 82614666.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×66641628² = 8882213164980768, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2776723 + ... + 2776746.

Almost surely, 2^66641628 is an apocalyptic number.

It is an amenable number.

66641628 is an abundant number, since it is smaller than the sum of its proper divisors (88855532).

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

66641628 is a wasteful number, since it uses less digits than its factorization.

66641628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5553476 (or 5553474 counting only the distinct ones).

The product of its digits is 82944, while the sum is 39.

The square root of 66641628 is about 8163.4323663518. The cubic root of 66641628 is about 405.4293632722.

The spelling of 66641628 in words is "sixty-six million, six hundred forty-one thousand, six hundred twenty-eight".