66149729 has 4 divisors (see below), whose sum is σ = 66337476. Its totient is φ = 65961984.

The previous prime is 66149723. The next prime is 66149749. The reversal of 66149729 is 92794166.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 41667025 + 24482704 = 6455^2 + 4948^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66149729 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66149729.

It is not an unprimeable number, because it can be changed into a prime (66149723) 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, 93344 + ... + 94049.

It is an arithmetic number, because the mean of its divisors is an integer number (16584369).

Almost surely, 2^66149729 is an apocalyptic number.

It is an amenable number.

66149729 is a deficient number, since it is larger than the sum of its proper divisors (187747).

66149729 is a wasteful number, since it uses less digits than its factorization.

66149729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187746.

The product of its digits is 163296, while the sum is 44.

The square root of 66149729 is about 8133.2483670425. The cubic root of 66149729 is about 404.4293726829.

The spelling of 66149729 in words is "sixty-six million, one hundred forty-nine thousand, seven hundred twenty-nine".