644102248 has 8 divisors (see below), whose sum is σ = 1207691730. Its totient is φ = 322051120.

The previous prime is 644102243. The next prime is 644102257. The reversal of 644102248 is 842201446.

It can be written as a sum of positive squares in only one way, i.e., 594286884 + 49815364 = 24378^2 + 7058^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (644102243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40256383 + ... + 40256398.

Almost surely, 2^644102248 is an apocalyptic number.

It is an amenable number.

644102248 is a deficient number, since it is larger than the sum of its proper divisors (563589482).

644102248 is a wasteful number, since it uses less digits than its factorization.

644102248 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80512787 (or 80512783 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 31.

The square root of 644102248 is about 25379.1695687625. The cubic root of 644102248 is about 863.6112112503.

The spelling of 644102248 in words is "six hundred forty-four million, one hundred two thousand, two hundred forty-eight".