81746957 has 2 divisors, whose sum is σ = 81746958. Its totient is φ = 81746956.

The previous prime is 81746953. The next prime is 81746963. The reversal of 81746957 is 75964718.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69538921 + 12208036 = 8339^2 + 3494^2 .

It is a cyclic number.

It is not a de Polignac number, because 81746957 - 2² = 81746953 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81746953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40873478 + 40873479.

It is an arithmetic number, because the mean of its divisors is an integer number (40873479).

Almost surely, 2^81746957 is an apocalyptic number.

It is an amenable number.

81746957 is a deficient number, since it is larger than the sum of its proper divisors (1).

81746957 is an equidigital number, since it uses as much as digits as its factorization.

81746957 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 423360, while the sum is 47.

The square root of 81746957 is about 9041.4023801621. The cubic root of 81746957 is about 434.0008016719. Note that the first 3 decimals are identical.

It can be divided in two parts, 817 and 46957, that added together give a palindrome (47774).

The spelling of 81746957 in words is "eighty-one million, seven hundred forty-six thousand, nine hundred fifty-seven".