81680520410 has 8 divisors (see below), whose sum is σ = 147024936756. Its totient is φ = 32672208160.

The previous prime is 81680520409. The next prime is 81680520431. The reversal of 81680520410 is 1402508618.

It can be written as a sum of positive squares in 2 ways, for example, as 80259456601 + 1421063809 = 283301^2 + 37697^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4084026011 + ... + 4084026030.

Almost surely, 2^81680520410 is an apocalyptic number.

81680520410 is a deficient number, since it is larger than the sum of its proper divisors (65344416346).

81680520410 is a wasteful number, since it uses less digits than its factorization.

81680520410 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8168052048.

The product of its (nonzero) digits is 15360, while the sum is 35.

The spelling of 81680520410 in words is "eighty-one billion, six hundred eighty million, five hundred twenty thousand, four hundred ten".