651721611 has 16 divisors (see below), whose sum is σ = 914169600. Its totient is φ = 412385568.

The previous prime is 651721597. The next prime is 651721643. The reversal of 651721611 is 116127156.

It is not a de Polignac number, because 651721611 - 2¹⁷ = 651590539 is a prime.

It is not an unprimeable number, because it can be changed into a prime (651721111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 58351 + ... + 68616.

It is an arithmetic number, because the mean of its divisors is an integer number (57135600).

Almost surely, 2^651721611 is an apocalyptic number.

651721611 is a deficient number, since it is larger than the sum of its proper divisors (262447989).

651721611 is a wasteful number, since it uses less digits than its factorization.

651721611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127058.

The product of its digits is 2520, while the sum is 30.

The square root of 651721611 is about 25528.8388102554. The cubic root of 651721611 is about 867.0032140833.

Adding to 651721611 its reverse (116127156), we get a palindrome (767848767).

The spelling of 651721611 in words is "six hundred fifty-one million, seven hundred twenty-one thousand, six hundred eleven".