644359581502 has 32 divisors (see below), whose sum is σ = 1191761851392. Its totient is φ = 254445426144.

The previous prime is 644359581499. The next prime is 644359581511. The reversal of 644359581502 is 205185953446.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 644359581502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3136678 + ... + 3335785.

It is an arithmetic number, because the mean of its divisors is an integer number (37242557856).

Almost surely, 2^644359581502 is an apocalyptic number.

644359581502 is a deficient number, since it is larger than the sum of its proper divisors (547402269890).

644359581502 is a wasteful number, since it uses less digits than its factorization.

644359581502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6473032.

The product of its (nonzero) digits is 5184000, while the sum is 52.

The spelling of 644359581502 in words is "six hundred forty-four billion, three hundred fifty-nine million, five hundred eighty-one thousand, five hundred two".