644634534 has 8 divisors (see below), whose sum is σ = 1289269080. Its totient is φ = 214878176.

The previous prime is 644634517. The next prime is 644634541. The reversal of 644634534 is 435436446.

It is a sphenic number, since it is the product of 3 distinct primes.

644634534 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 644634492 and 644634501.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53719539 + ... + 53719550.

It is an arithmetic number, because the mean of its divisors is an integer number (161158635).

Almost surely, 2^644634534 is an apocalyptic number.

644634534 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

644634534 is a wasteful number, since it uses less digits than its factorization.

644634534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107439094.

The product of its digits is 414720, while the sum is 39.

The square root of 644634534 is about 25389.6540740515. The cubic root of 644634534 is about 863.8490418060.

The spelling of 644634534 in words is "six hundred forty-four million, six hundred thirty-four thousand, five hundred thirty-four".