81194773805494 has 8 divisors (see below), whose sum is σ = 121930090677720. Its totient is φ = 40551410246256.

The previous prime is 81194773805471. The next prime is 81194773805501. The reversal of 81194773805494 is 49450837749118.

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

It is a super-2 number, since 2×81194773805494² (a number of 29 digits) contains 22 as substring.

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, 22988326039 + ... + 22988329570.

It is an arithmetic number, because the mean of its divisors is an integer number (15241261334715).

Almost surely, 2^{81194773805494} is an apocalyptic number.

81194773805494 is a deficient number, since it is larger than the sum of its proper divisors (40735316872226).

81194773805494 is a wasteful number, since it uses less digits than its factorization.

81194773805494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45976656494.

The product of its (nonzero) digits is 243855360, while the sum is 70.

The spelling of 81194773805494 in words is "eighty-one trillion, one hundred ninety-four billion, seven hundred seventy-three million, eight hundred five thousand, four hundred ninety-four".