81400894 has 8 divisors (see below), whose sum is σ = 122209128. Its totient is φ = 40664520.

The previous prime is 81400871. The next prime is 81400961. The reversal of 81400894 is 49800418.

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

It is a super-2 number, since 2×81400894² = 13252211087998472, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15037 + ... + 19720.

It is an arithmetic number, because the mean of its divisors is an integer number (15276141).

Almost surely, 2^81400894 is an apocalyptic number.

81400894 is a deficient number, since it is larger than the sum of its proper divisors (40808234).

81400894 is a wasteful number, since it uses less digits than its factorization.

81400894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35930.

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

The square root of 81400894 is about 9022.2443992612. The cubic root of 81400894 is about 433.3875105175.

The spelling of 81400894 in words is "eighty-one million, four hundred thousand, eight hundred ninety-four".