644460233153 has 4 divisors (see below), whose sum is σ = 703047527088. Its totient is φ = 585872939220.

The previous prime is 644460233129. The next prime is 644460233161. The reversal of 644460233153 is 351332064446.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644460233153 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 644460233153.

It is not an unprimeable number, because it can be changed into a prime (644460236153) 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, 29293646951 + ... + 29293646972.

It is an arithmetic number, because the mean of its divisors is an integer number (175761881772).

Almost surely, 2^644460233153 is an apocalyptic number.

It is an amenable number.

644460233153 is a deficient number, since it is larger than the sum of its proper divisors (58587293935).

644460233153 is a wasteful number, since it uses less digits than its factorization.

644460233153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58587293934.

The product of its (nonzero) digits is 622080, while the sum is 41.

Adding to 644460233153 its reverse (351332064446), we get a palindrome (995792297599).

The spelling of 644460233153 in words is "six hundred forty-four billion, four hundred sixty million, two hundred thirty-three thousand, one hundred fifty-three".