81634831 has 2 divisors, whose sum is σ = 81634832. Its totient is φ = 81634830.

The previous prime is 81634829. The next prime is 81634859. The reversal of 81634831 is 13843618.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81634831 - 2¹ = 81634829 is a prime.

It is a super-2 number, since 2×81634831² = 13328491264797122, which contains 22 as substring.

Together with 81634829, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81634871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40817415 + 40817416.

It is an arithmetic number, because the mean of its divisors is an integer number (40817416).

Almost surely, 2^81634831 is an apocalyptic number.

81634831 is a deficient number, since it is larger than the sum of its proper divisors (1).

81634831 is an equidigital number, since it uses as much as digits as its factorization.

81634831 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13824, while the sum is 34.

The square root of 81634831 is about 9035.1995550735. The cubic root of 81634831 is about 433.8022823972.

The spelling of 81634831 in words is "eighty-one million, six hundred thirty-four thousand, eight hundred thirty-one".