650000721 has 8 divisors (see below), whose sum is σ = 869797504. Its totient is φ = 431768880.

The previous prime is 650000713. The next prime is 650000737. The reversal of 650000721 is 127000056.

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

It is not a de Polignac number, because 650000721 - 2³ = 650000713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (650002721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 390265 + ... + 391926.

It is an arithmetic number, because the mean of its divisors is an integer number (108724688).

Almost surely, 2^650000721 is an apocalyptic number.

It is an amenable number.

650000721 is a deficient number, since it is larger than the sum of its proper divisors (219796783).

650000721 is a wasteful number, since it uses less digits than its factorization.

650000721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 782471.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 650000721 is about 25495.1117079333. Note that the first 3 decimals coincide. The cubic root of 650000721 is about 866.2394256271.

Adding to 650000721 its reverse (127000056), we get a palindrome (777000777).

The spelling of 650000721 in words is "six hundred fifty million, seven hundred twenty-one", and thus it is an aban number.