81000756349 has 4 divisors (see below), whose sum is σ = 81016401760. Its totient is φ = 80985110940.

The previous prime is 81000756301. The next prime is 81000756383. The reversal of 81000756349 is 94365700018.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81000756349 - 2²¹ = 80998659197 is a prime.

It is a super-2 number, since 2×81000756349² (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 (81000756149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7814937 + ... + 7825294.

It is an arithmetic number, because the mean of its divisors is an integer number (20254100440).

Almost surely, 2^81000756349 is an apocalyptic number.

It is an amenable number.

81000756349 is a deficient number, since it is larger than the sum of its proper divisors (15645411).

81000756349 is a wasteful number, since it uses less digits than its factorization.

81000756349 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15645410.

The product of its (nonzero) digits is 181440, while the sum is 43.

The spelling of 81000756349 in words is "eighty-one billion, seven hundred fifty-six thousand, three hundred forty-nine".