81497621317 has 8 divisors (see below), whose sum is σ = 95306188736. Its totient is φ = 68230566432.

The previous prime is 81497621237. The next prime is 81497621323. The reversal of 81497621317 is 71312679418.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81497621317 - 2¹⁹ = 81497097029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81497621327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 135377808 + ... + 135378409.

It is an arithmetic number, because the mean of its divisors is an integer number (11913273592).

Almost surely, 2^81497621317 is an apocalyptic number.

It is an amenable number.

81497621317 is a deficient number, since it is larger than the sum of its proper divisors (13808567419).

81497621317 is a wasteful number, since it uses less digits than its factorization.

81497621317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270756267.

The product of its digits is 508032, while the sum is 49.

The spelling of 81497621317 in words is "eighty-one billion, four hundred ninety-seven million, six hundred twenty-one thousand, three hundred seventeen".