650721721 has 8 divisors (see below), whose sum is σ = 715688064. Its totient is φ = 587885520.

The previous prime is 650721719. The next prime is 650721739. The reversal of 650721721 is 127127056.

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

It is a cyclic number.

It is not a de Polignac number, because 650721721 - 2¹ = 650721719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (650721791) 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, 531895 + ... + 533116.

It is an arithmetic number, because the mean of its divisors is an integer number (89461008).

Almost surely, 2^650721721 is an apocalyptic number.

It is an amenable number.

650721721 is a deficient number, since it is larger than the sum of its proper divisors (64966343).

650721721 is a wasteful number, since it uses less digits than its factorization.

650721721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1065071.

The product of its (nonzero) digits is 5880, while the sum is 31.

The square root of 650721721 is about 25509.2477544909. The cubic root of 650721721 is about 866.5595933960.

Adding to 650721721 its reverse (127127056), we get a palindrome (777848777).

The spelling of 650721721 in words is "six hundred fifty million, seven hundred twenty-one thousand, seven hundred twenty-one".