66191004 has 36 divisors (see below), whose sum is σ = 182527800. Its totient is φ = 20057760.

The previous prime is 66190997. The next prime is 66191009. The reversal of 66191004 is 40019166.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66191009) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 83179 + ... + 83970.

Almost surely, 2^66191004 is an apocalyptic number.

It is an amenable number.

66191004 is an abundant number, since it is smaller than the sum of its proper divisors (116336796).

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

66191004 is a wasteful number, since it uses less digits than its factorization.

66191004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167170 (or 167165 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 66191004 is about 8135.7853953998. The cubic root of 66191004 is about 404.5134715492.

The spelling of 66191004 in words is "sixty-six million, one hundred ninety-one thousand, four".