66722491 has 8 divisors (see below), whose sum is σ = 73062000. Its totient is φ = 60428640.

The previous prime is 66722479. The next prime is 66722527. The reversal of 66722491 is 19422766.

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 66722491 - 2¹¹ = 66720443 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66722491.

It is not an unprimeable number, because it can be changed into a prime (66722441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8316 + ... + 14233.

It is an arithmetic number, because the mean of its divisors is an integer number (9132750).

Almost surely, 2^66722491 is an apocalyptic number.

66722491 is a deficient number, since it is larger than the sum of its proper divisors (6339509).

66722491 is a wasteful number, since it uses less digits than its factorization.

66722491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22829.

The product of its digits is 36288, while the sum is 37.

The square root of 66722491 is about 8168.3836222352. The cubic root of 66722491 is about 405.5932797529.

The spelling of 66722491 in words is "sixty-six million, seven hundred twenty-two thousand, four hundred ninety-one".