651631231 has 4 divisors (see below), whose sum is σ = 651999712. Its totient is φ = 651262752.

The previous prime is 651631229. The next prime is 651631243. The reversal of 651631231 is 132136156.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 651631231 - 2¹ = 651631229 is a prime.

It is a super-3 number, since 3×651631231³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 651631231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (651631261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 181575 + ... + 185128.

It is an arithmetic number, because the mean of its divisors is an integer number (162999928).

Almost surely, 2^651631231 is an apocalyptic number.

651631231 is a deficient number, since it is larger than the sum of its proper divisors (368481).

651631231 is a wasteful number, since it uses less digits than its factorization.

651631231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 368480.

The product of its digits is 3240, while the sum is 28.

The square root of 651631231 is about 25527.0685939455. The cubic root of 651631231 is about 866.9631338958.

Adding to 651631231 its reverse (132136156), we get a palindrome (783767387).

The spelling of 651631231 in words is "six hundred fifty-one million, six hundred thirty-one thousand, two hundred thirty-one".