81491509314 has 24 divisors (see below), whose sum is σ = 185857829040. Its totient is φ = 25734160728.

The previous prime is 81491509283. The next prime is 81491509339. The reversal of 81491509314 is 41390519418.

81491509314 is a `hidden beast` number, since 81 + 491 + 50 + 9 + 31 + 4 = 666.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 81491509314.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 119139292 + ... + 119139975.

It is an arithmetic number, because the mean of its divisors is an integer number (7744076210).

Almost surely, 2^81491509314 is an apocalyptic number.

81491509314 is an abundant number, since it is smaller than the sum of its proper divisors (104366319726).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81491509314 is a wasteful number, since it uses less digits than its factorization.

81491509314 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238279294 (or 238279291 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 45.

The spelling of 81491509314 in words is "eighty-one billion, four hundred ninety-one million, five hundred nine thousand, three hundred fourteen".