81698104457 has 8 divisors (see below), whose sum is σ = 83244288384. Its totient is φ = 80152095088.

The previous prime is 81698104421. The next prime is 81698104463. The reversal of 81698104457 is 75440189618.

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

It is a cyclic number.

It is not a de Polignac number, because 81698104457 - 2⁶ = 81698104393 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (53).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81698104399 and 81698104408.

It is not an unprimeable number, because it can be changed into a prime (81698104487) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1273718 + ... + 1336320.

It is an arithmetic number, because the mean of its divisors is an integer number (10405536048).

Almost surely, 2^81698104457 is an apocalyptic number.

It is an amenable number.

81698104457 is a deficient number, since it is larger than the sum of its proper divisors (1546183927).

81698104457 is a wasteful number, since it uses less digits than its factorization.

81698104457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87279.

The product of its (nonzero) digits is 1935360, while the sum is 53.

The spelling of 81698104457 in words is "eighty-one billion, six hundred ninety-eight million, one hundred four thousand, four hundred fifty-seven".