66261261 has 8 divisors (see below), whose sum is σ = 96380064. Its totient is φ = 40158320.

The previous prime is 66261199. The next prime is 66261269. The reversal of 66261261 is 16216266.

66261261 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 66261261 - 2⁶ = 66261197 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66261269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1003926 + ... + 1003991.

It is an arithmetic number, because the mean of its divisors is an integer number (12047508).

Almost surely, 2^66261261 is an apocalyptic number.

It is an amenable number.

66261261 is a deficient number, since it is larger than the sum of its proper divisors (30118803).

66261261 is a wasteful number, since it uses less digits than its factorization.

66261261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2007931.

The product of its digits is 5184, while the sum is 30.

The square root of 66261261 is about 8140.1020263876. The cubic root of 66261261 is about 404.6565416139.

It can be divided in two parts, 6626 and 1261, that added together give a palindrome (7887).

The spelling of 66261261 in words is "sixty-six million, two hundred sixty-one thousand, two hundred sixty-one".