81806374 has 8 divisors (see below), whose sum is σ = 132148800. Its totient is φ = 37756776.

The previous prime is 81806341. The next prime is 81806383. The reversal of 81806374 is 47360818.

It is a happy number.

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, 1573174 + ... + 1573225.

It is an arithmetic number, because the mean of its divisors is an integer number (16518600).

Almost surely, 2^81806374 is an apocalyptic number.

81806374 is a deficient number, since it is larger than the sum of its proper divisors (50342426).

81806374 is a wasteful number, since it uses less digits than its factorization.

81806374 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3146414.

The product of its (nonzero) digits is 32256, while the sum is 37.

The square root of 81806374 is about 9044.6876120737. The cubic root of 81806374 is about 434.1059259947.

The spelling of 81806374 in words is "eighty-one million, eight hundred six thousand, three hundred seventy-four".