81617056826 has 8 divisors (see below), whose sum is σ = 122481164064. Its totient is φ = 40790002140.

The previous prime is 81617056823. The next prime is 81617056853. The reversal of 81617056826 is 62865071618.

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

It is a super-2 number, since 2×81617056826² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81617056823) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9257630 + ... + 9266441.

It is an arithmetic number, because the mean of its divisors is an integer number (15310145508).

Almost surely, 2^81617056826 is an apocalyptic number.

81617056826 is a deficient number, since it is larger than the sum of its proper divisors (40864107238).

81617056826 is a wasteful number, since it uses less digits than its factorization.

81617056826 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18526276.

The product of its (nonzero) digits is 967680, while the sum is 50.

The spelling of 81617056826 in words is "eighty-one billion, six hundred seventeen million, fifty-six thousand, eight hundred twenty-six".