646545700 has 72 divisors (see below), whose sum is σ = 1491982632. Its totient is φ = 242350080.

The previous prime is 646545689. The next prime is 646545727. The reversal of 646545700 is 7545646.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 32695524 + 613850176 = 5718^2 + 24776^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 646545700.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 470214 + ... + 471586.

It is an arithmetic number, because the mean of its divisors is an integer number (20721981).

Almost surely, 2^646545700 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646545700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (745991316).

646545700 is an abundant number, since it is smaller than the sum of its proper divisors (845436932).

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

646545700 is a wasteful number, since it uses less digits than its factorization.

646545700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1681 (or 1674 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 37.

The square root of 646545700 is about 25427.2629278104. The cubic root of 646545700 is about 864.7018919946.

The spelling of 646545700 in words is "six hundred forty-six million, five hundred forty-five thousand, seven hundred".