81400008166 has 8 divisors (see below), whose sum is σ = 122104292184. Its totient is φ = 40698577440.

The previous prime is 81400008127. The next prime is 81400008169. The reversal of 81400008166 is 66180000418.

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

It is a super-2 number, since 2×81400008166² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81400008169) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 640515 + ... + 757006.

It is an arithmetic number, because the mean of its divisors is an integer number (15263036523).

Almost surely, 2^81400008166 is an apocalyptic number.

81400008166 is a deficient number, since it is larger than the sum of its proper divisors (40704284018).

81400008166 is a wasteful number, since it uses less digits than its factorization.

81400008166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1426646.

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

The spelling of 81400008166 in words is "eighty-one billion, four hundred million, eight thousand, one hundred sixty-six".