664111261 has 8 divisors (see below), whose sum is σ = 744066144. Its totient is φ = 587419920.

The previous prime is 664111247. The next prime is 664111271. The reversal of 664111261 is 162111466.

664111261 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 664111261 - 2⁹ = 664110749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664111271) 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, 815455 + ... + 816268.

It is an arithmetic number, because the mean of its divisors is an integer number (93008268).

Almost surely, 2^664111261 is an apocalyptic number.

It is an amenable number.

664111261 is a deficient number, since it is larger than the sum of its proper divisors (79954883).

664111261 is a wasteful number, since it uses less digits than its factorization.

664111261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1631771.

The product of its digits is 1728, while the sum is 28.

The square root of 664111261 is about 25770.3562451123. The cubic root of 664111261 is about 872.4628593151.

The spelling of 664111261 in words is "six hundred sixty-four million, one hundred eleven thousand, two hundred sixty-one".