81262231 has 2 divisors, whose sum is σ = 81262232. Its totient is φ = 81262230.

The previous prime is 81262211. The next prime is 81262267. The reversal of 81262231 is 13226218.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81262231 - 2⁵ = 81262199 is a prime.

It is a super-2 number, since 2×81262231² = 13207100374194722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81262196 and 81262205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81262211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40631115 + 40631116.

It is an arithmetic number, because the mean of its divisors is an integer number (40631116).

Almost surely, 2^81262231 is an apocalyptic number.

81262231 is a deficient number, since it is larger than the sum of its proper divisors (1).

81262231 is an equidigital number, since it uses as much as digits as its factorization.

81262231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152, while the sum is 25.

The square root of 81262231 is about 9014.5566169391. The cubic root of 81262231 is about 433.1412848528.

Adding to 81262231 its reverse (13226218), we get a palindrome (94488449).

The spelling of 81262231 in words is "eighty-one million, two hundred sixty-two thousand, two hundred thirty-one".