51643231 has 16 divisors (see below), whose sum is σ = 55349280. Its totient is φ = 48107520.

The previous prime is 51643223. The next prime is 51643237. The reversal of 51643231 is 13234615.

It is a cyclic number.

It is not a de Polignac number, because 51643231 - 2³ = 51643223 is a prime.

It is a super-2 number, since 2×51643231² = 5334046616238722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51643196 and 51643205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51643237) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 89215 + ... + 89791.

It is an arithmetic number, because the mean of its divisors is an integer number (3459330).

Almost surely, 2^51643231 is an apocalyptic number.

51643231 is a deficient number, since it is larger than the sum of its proper divisors (3706049).

51643231 is a wasteful number, since it uses less digits than its factorization.

51643231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 714.

The product of its digits is 2160, while the sum is 25.

The square root of 51643231 is about 7186.3224948509. The cubic root of 51643231 is about 372.3955378745.

Adding to 51643231 its reverse (13234615), we get a palindrome (64877846).

The spelling of 51643231 in words is "fifty-one million, six hundred forty-three thousand, two hundred thirty-one".