81401686 has 8 divisors (see below), whose sum is σ = 122230440. Its totient is φ = 40658208.

The previous prime is 81401659. The next prime is 81401699. The reversal of 81401686 is 68610418.

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

It is a congruent number.

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, 18876 + ... + 22783.

It is an arithmetic number, because the mean of its divisors is an integer number (15278805).

Almost surely, 2^81401686 is an apocalyptic number.

81401686 is a deficient number, since it is larger than the sum of its proper divisors (40828754).

81401686 is a wasteful number, since it uses less digits than its factorization.

81401686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42638.

The product of its (nonzero) digits is 9216, while the sum is 34.

The square root of 81401686 is about 9022.2882906722. The cubic root of 81401686 is about 433.3889160786.

The spelling of 81401686 in words is "eighty-one million, four hundred one thousand, six hundred eighty-six".