650721618 has 24 divisors (see below), whose sum is σ = 1411913100. Its totient is φ = 216597024.

The previous prime is 650721613. The next prime is 650721637. The reversal of 650721618 is 816127056.

It can be written as a sum of positive squares in 2 ways, for example, as 627652809 + 23068809 = 25053^2 + 4803^2 .

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (650721613) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12733 + ... + 38256.

Almost surely, 2^650721618 is an apocalyptic number.

650721618 is an abundant number, since it is smaller than the sum of its proper divisors (761191482).

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

650721618 is a wasteful number, since it uses less digits than its factorization.

650721618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51706 (or 51703 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 650721618 is about 25509.2457356152. The cubic root of 650721618 is about 866.5595476746.

The spelling of 650721618 in words is "six hundred fifty million, seven hundred twenty-one thousand, six hundred eighteen".