81400383291 has 4 divisors (see below), whose sum is σ = 108533844392. Its totient is φ = 54266922192.

The previous prime is 81400383287. The next prime is 81400383341. The reversal of 81400383291 is 19238300418.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 81400383291 - 2² = 81400383287 is a prime.

It is a super-3 number, since 3×81400383291³ (a number of 34 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81400383221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13566730546 + ... + 13566730551.

It is an arithmetic number, because the mean of its divisors is an integer number (27133461098).

Almost surely, 2^81400383291 is an apocalyptic number.

81400383291 is a deficient number, since it is larger than the sum of its proper divisors (27133461101).

81400383291 is a wasteful number, since it uses less digits than its factorization.

81400383291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27133461100.

The product of its (nonzero) digits is 41472, while the sum is 39.

The spelling of 81400383291 in words is "eighty-one billion, four hundred million, three hundred eighty-three thousand, two hundred ninety-one".