81403477767 has 80 divisors (see below), whose sum is σ = 124766840352. Its totient is φ = 52881776640.

The previous prime is 81403477733. The next prime is 81403477769. The reversal of 81403477767 is 76777430418.

It is a happy number.

It is not a de Polignac number, because 81403477767 - 2⁶ = 81403477703 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81403477769) 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 79 ways as a sum of consecutive naturals, for example, 245931792 + ... + 245932122.

Almost surely, 2^81403477767 is an apocalyptic number.

81403477767 is a deficient number, since it is larger than the sum of its proper divisors (43363362585).

81403477767 is a wasteful number, since it uses less digits than its factorization.

81403477767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 830 (or 821 counting only the distinct ones).

The product of its (nonzero) digits is 5531904, while the sum is 54.

The spelling of 81403477767 in words is "eighty-one billion, four hundred three million, four hundred seventy-seven thousand, seven hundred sixty-seven".