644102534 has 32 divisors (see below), whose sum is σ = 1031486400. Its totient is φ = 300972672.

The previous prime is 644102533. The next prime is 644102551. The reversal of 644102534 is 435201446.

It is a junction number, because it is equal to n+sod(n) for n = 644102497 and 644102506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644102533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 850484 + ... + 851240.

It is an arithmetic number, because the mean of its divisors is an integer number (32233950).

Almost surely, 2^644102534 is an apocalyptic number.

644102534 is a deficient number, since it is larger than the sum of its proper divisors (387383866).

644102534 is a wasteful number, since it uses less digits than its factorization.

644102534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1184.

The product of its (nonzero) digits is 11520, while the sum is 29.

The square root of 644102534 is about 25379.1752033040. The cubic root of 644102534 is about 863.6113390731.

The spelling of 644102534 in words is "six hundred forty-four million, one hundred two thousand, five hundred thirty-four".