644204234790999 has 24 divisors (see below), whose sum is σ = 932579527606272. Its totient is φ = 428518048240080.

The previous prime is 644204234790971. The next prime is 644204234791003. The reversal of 644204234790999 is 999097432402446.

It is a happy number.

644204234790999 is a `hidden beast` number, since 6 + 4 + 4 + 20 + 42 + 3 + 479 + 0 + 9 + 99 = 666.

It is not a de Polignac number, because 644204234790999 - 2⁷ = 644204234790871 is a prime.

It is a super-2 number, since 2×644204234790999² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644204234790959) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3674154 + ... + 36081960.

It is an arithmetic number, because the mean of its divisors is an integer number (38857480316928).

Almost surely, 2^{644204234790999} is an apocalyptic number.

644204234790999 is a deficient number, since it is larger than the sum of its proper divisors (288375292815273).

644204234790999 is a wasteful number, since it uses less digits than its factorization.

644204234790999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32412707 (or 32412704 counting only the distinct ones).

The product of its (nonzero) digits is 846526464, while the sum is 72.

The spelling of 644204234790999 in words is "six hundred forty-four trillion, two hundred four billion, two hundred thirty-four million, seven hundred ninety thousand, nine hundred ninety-nine".