81823157872661 has 8 divisors (see below), whose sum is σ = 82474914800640. Its totient is φ = 81171517821408.

The previous prime is 81823157872627. The next prime is 81823157872663. The reversal of 81823157872661 is 16627875132818.

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 81823157872661 - 2⁶ = 81823157872597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81823157872663) 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 7 ways as a sum of consecutive naturals, for example, 27813176 + ... + 30614033.

It is an arithmetic number, because the mean of its divisors is an integer number (10309364350080).

Almost surely, 2^{81823157872661} is an apocalyptic number.

It is an amenable number.

81823157872661 is a deficient number, since it is larger than the sum of its proper divisors (651756927979).

81823157872661 is a wasteful number, since it uses less digits than its factorization.

81823157872661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58438363.

The product of its digits is 54190080, while the sum is 65.

The spelling of 81823157872661 in words is "eighty-one trillion, eight hundred twenty-three billion, one hundred fifty-seven million, eight hundred seventy-two thousand, six hundred sixty-one".