644210147 has 16 divisors (see below), whose sum is σ = 763791360. Its totient is φ = 531625248.

The previous prime is 644210141. The next prime is 644210179. The reversal of 644210147 is 741012446.

It is a happy number.

It is not a de Polignac number, because 644210147 - 2¹⁰ = 644209123 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644210141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 70178 + ... + 78824.

It is an arithmetic number, because the mean of its divisors is an integer number (47736960).

Almost surely, 2^644210147 is an apocalyptic number.

644210147 is a deficient number, since it is larger than the sum of its proper divisors (119581213).

644210147 is a wasteful number, since it uses less digits than its factorization.

644210147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9050.

The product of its (nonzero) digits is 5376, while the sum is 29.

The square root of 644210147 is about 25381.2952191176. The cubic root of 644210147 is about 863.6594321571.

The spelling of 644210147 in words is "six hundred forty-four million, two hundred ten thousand, one hundred forty-seven".