644777546 has 32 divisors (see below), whose sum is σ = 1119191040. Its totient is φ = 272890800.

The previous prime is 644777533. The next prime is 644777569. The reversal of 644777546 is 645777446.

It is a junction number, because it is equal to n+sod(n) for n = 644777494 and 644777503.

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, 437591 + ... + 439061.

It is an arithmetic number, because the mean of its divisors is an integer number (34974720).

Almost surely, 2^644777546 is an apocalyptic number.

644777546 is a deficient number, since it is larger than the sum of its proper divisors (474413494).

644777546 is a wasteful number, since it uses less digits than its factorization.

644777546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1850.

The product of its digits is 3951360, while the sum is 50.

The square root of 644777546 is about 25392.4702618709. The cubic root of 644777546 is about 863.9129186426.

The spelling of 644777546 in words is "six hundred forty-four million, seven hundred seventy-seven thousand, five hundred forty-six".