81591029471 has 8 divisors (see below), whose sum is σ = 98154622080. Its totient is φ = 66254369688.

The previous prime is 81591029461. The next prime is 81591029473. The reversal of 81591029471 is 17492019518.

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

It is a cyclic number.

It is not a de Polignac number, because 81591029471 - 2¹⁴ = 81591013087 is a prime.

It is a super-3 number, since 3×81591029471³ (a number of 34 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81591029473) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 306733061 + ... + 306733326.

It is an arithmetic number, because the mean of its divisors is an integer number (12269327760).

Almost surely, 2^81591029471 is an apocalyptic number.

81591029471 is a deficient number, since it is larger than the sum of its proper divisors (16563592609).

81591029471 is a wasteful number, since it uses less digits than its factorization.

81591029471 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 613466413.

The product of its (nonzero) digits is 181440, while the sum is 47.

The spelling of 81591029471 in words is "eighty-one billion, five hundred ninety-one million, twenty-nine thousand, four hundred seventy-one".