644306157330 has 128 divisors (see below), whose sum is σ = 1693614790656. Its totient is φ = 155575987200.

The previous prime is 644306157323. The next prime is 644306157331. The reversal of 644306157330 is 33751603446.

It is not an unprimeable number, because it can be changed into a prime (644306157331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 90476170 + ... + 90483290.

It is an arithmetic number, because the mean of its divisors is an integer number (13231365552).

Almost surely, 2^644306157330 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644306157330, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (846807395328).

644306157330 is an abundant number, since it is smaller than the sum of its proper divisors (1049308633326).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644306157330 is a wasteful number, since it uses less digits than its factorization.

644306157330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8192.

The product of its (nonzero) digits is 544320, while the sum is 42.

The spelling of 644306157330 in words is "six hundred forty-four billion, three hundred six million, one hundred fifty-seven thousand, three hundred thirty".