81784039402641 has 8 divisors (see below), whose sum is σ = 109053827927424. Its totient is φ = 54518471906480.

The previous prime is 81784039402633. The next prime is 81784039402661. The reversal of 81784039402641 is 14620493048718.

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 81784039402641 - 2³ = 81784039402633 is a prime.

It is a super-2 number, since 2×81784039402641² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81784039402661) 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 7 ways as a sum of consecutive naturals, for example, 1055211945 + ... + 1055289446.

It is an arithmetic number, because the mean of its divisors is an integer number (13631728490928).

Almost surely, 2^{81784039402641} is an apocalyptic number.

It is an amenable number.

81784039402641 is a deficient number, since it is larger than the sum of its proper divisors (27269788524783).

81784039402641 is a wasteful number, since it uses less digits than its factorization.

81784039402641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2110514311.

The product of its (nonzero) digits is 9289728, while the sum is 57.

The spelling of 81784039402641 in words is "eighty-one trillion, seven hundred eighty-four billion, thirty-nine million, four hundred two thousand, six hundred forty-one".