81403670511 has 96 divisors (see below), whose sum is σ = 125483904000. Its totient is φ = 50790115584.

The previous prime is 81403670501. The next prime is 81403670527. The reversal of 81403670511 is 11507630418.

81403670511 is a `hidden beast` number, since 8 + 1 + 40 + 36 + 70 + 511 = 666.

It is not a de Polignac number, because 81403670511 - 2¹⁸ = 81403408367 is a prime.

It is a super-2 number, since 2×81403670511² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81403670501) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 277828081 + ... + 277828373.

It is an arithmetic number, because the mean of its divisors is an integer number (1307124000).

Almost surely, 2^81403670511 is an apocalyptic number.

81403670511 is a deficient number, since it is larger than the sum of its proper divisors (44080233489).

81403670511 is a wasteful number, since it uses less digits than its factorization.

81403670511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 653 (or 650 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The spelling of 81403670511 in words is "eighty-one billion, four hundred three million, six hundred seventy thousand, five hundred eleven".