81908356362496 has 18 divisors (see below), whose sum is σ = 163496758208462. Its totient is φ = 40954178181120.

The previous prime is 81908356362491. The next prime is 81908356362523. The reversal of 81908356362496 is 69426365380918.

It can be written as a sum of positive squares in only one way, i.e., 49732960665600 + 32175395696896 = 7052160^2 + 5672336^2 .

It is not an unprimeable number, because it can be changed into a prime (81908356362491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159977258265 + ... + 159977258776.

Almost surely, 2^{81908356362496} is an apocalyptic number.

It is an amenable number.

81908356362496 is a deficient number, since it is larger than the sum of its proper divisors (81588401845966).

81908356362496 is an equidigital number, since it uses as much as digits as its factorization.

81908356362496 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319954517057 (or 319954517043 counting only the distinct ones).

The product of its (nonzero) digits is 403107840, while the sum is 70.

The spelling of 81908356362496 in words is "eighty-one trillion, nine hundred eight billion, three hundred fifty-six million, three hundred sixty-two thousand, four hundred ninety-six".