81291957373 has 8 divisors (see below), whose sum is σ = 91078950240. Its totient is φ = 71904433680.

The previous prime is 81291957337. The next prime is 81291957403. The reversal of 81291957373 is 37375919218.

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 81291957373 - 2¹³ = 81291949181 is a prime.

It is a super-2 number, since 2×81291957373² (a number of 23 digits) contains 22 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 (81291957323) 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, 99866863 + ... + 99867676.

It is an arithmetic number, because the mean of its divisors is an integer number (11384868780).

Almost surely, 2^81291957373 is an apocalyptic number.

It is an amenable number.

81291957373 is a deficient number, since it is larger than the sum of its proper divisors (9786992867).

81291957373 is a wasteful number, since it uses less digits than its factorization.

81291957373 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199734587.

The product of its digits is 2857680, while the sum is 55.

The spelling of 81291957373 in words is "eighty-one billion, two hundred ninety-one million, nine hundred fifty-seven thousand, three hundred seventy-three".