81403477766 has 32 divisors (see below), whose sum is σ = 137256251328. Its totient is φ = 35926577280.

The previous prime is 81403477733. The next prime is 81403477769. The reversal of 81403477766 is 66777430418.

It is a Curzon number.

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 polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2180336 + ... + 2217356.

It is an arithmetic number, because the mean of its divisors is an integer number (4289257854).

Almost surely, 2^81403477766 is an apocalyptic number.

81403477766 is a deficient number, since it is larger than the sum of its proper divisors (55852773562).

81403477766 is a wasteful number, since it uses less digits than its factorization.

81403477766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40736.

The product of its (nonzero) digits is 4741632, while the sum is 53.

The spelling of 81403477766 in words is "eighty-one billion, four hundred three million, four hundred seventy-seven thousand, seven hundred sixty-six".