81350600781 has 8 divisors (see below), whose sum is σ = 108981532384. Its totient is φ = 53976701520.

The previous prime is 81350600777. The next prime is 81350600833. The reversal of 81350600781 is 18700605318.

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

It is not a de Polignac number, because 81350600781 - 2² = 81350600777 is a prime.

It is a super-2 number, since 2×81350600781² (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 (81350600761) 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, 64257346 + ... + 64258611.

It is an arithmetic number, because the mean of its divisors is an integer number (13622691548).

Almost surely, 2^81350600781 is an apocalyptic number.

It is an amenable number.

81350600781 is a deficient number, since it is larger than the sum of its proper divisors (27630931603).

81350600781 is a wasteful number, since it uses less digits than its factorization.

81350600781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128516171.

The product of its (nonzero) digits is 40320, while the sum is 39.

The spelling of 81350600781 in words is "eighty-one billion, three hundred fifty million, six hundred thousand, seven hundred eighty-one".