6644654129 has 4 divisors (see below), whose sum is σ = 6651716340. Its totient is φ = 6637591920.

The previous prime is 6644654123. The next prime is 6644654131. The reversal of 6644654129 is 9214564466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9214564466 = 2 ⋅4607282233.

It can be written as a sum of positive squares in 2 ways, for example, as 2232373504 + 4412280625 = 47248^2 + 66425^2 .

It is a cyclic number.

It is not a de Polignac number, because 6644654129 - 2¹⁶ = 6644588593 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6644654123) 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, 3529694 + ... + 3531575.

It is an arithmetic number, because the mean of its divisors is an integer number (1662929085).

Almost surely, 2^6644654129 is an apocalyptic number.

It is an amenable number.

6644654129 is a deficient number, since it is larger than the sum of its proper divisors (7062211).

6644654129 is an equidigital number, since it uses as much as digits as its factorization.

6644654129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7062210.

The product of its digits is 1244160, while the sum is 47.

The square root of 6644654129 is about 81514.7479233053. The cubic root of 6644654129 is about 1879.9983145639.

The spelling of 6644654129 in words is "six billion, six hundred forty-four million, six hundred fifty-four thousand, one hundred twenty-nine".