51031231 has 2 divisors, whose sum is σ = 51031232. Its totient is φ = 51031230.

The previous prime is 51031217. The next prime is 51031241. The reversal of 51031231 is 13213015.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 51031231 - 2⁵ = 51031199 is a prime.

It is a super-2 number, since 2×51031231² = 5208373074750722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51031241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25515615 + 25515616.

It is an arithmetic number, because the mean of its divisors is an integer number (25515616).

Almost surely, 2^51031231 is an apocalyptic number.

51031231 is a deficient number, since it is larger than the sum of its proper divisors (1).

51031231 is an equidigital number, since it uses as much as digits as its factorization.

51031231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90, while the sum is 16.

The square root of 51031231 is about 7143.6147012559. The cubic root of 51031231 is about 370.9186594998.

Adding to 51031231 its reverse (13213015), we get a palindrome (64244246).

The spelling of 51031231 in words is "fifty-one million, thirty-one thousand, two hundred thirty-one".