66181954 has 8 divisors (see below), whose sum is σ = 101694348. Its totient is φ = 32283840.

The previous prime is 66181949. The next prime is 66181957. The reversal of 66181954 is 45918166.

It can be written as a sum of positive squares in 2 ways, for example, as 55845729 + 10336225 = 7473^2 + 3215^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (66181957) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 403467 + ... + 403630.

Almost surely, 2^66181954 is an apocalyptic number.

66181954 is a deficient number, since it is larger than the sum of its proper divisors (35512394).

66181954 is a wasteful number, since it uses less digits than its factorization.

66181954 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 807140.

The product of its digits is 51840, while the sum is 40.

The square root of 66181954 is about 8135.2291916086. The cubic root of 66181954 is about 404.4950349363.

The spelling of 66181954 in words is "sixty-six million, one hundred eighty-one thousand, nine hundred fifty-four".