81630784726 has 4 divisors (see below), whose sum is σ = 122446177092. Its totient is φ = 40815392362.

The previous prime is 81630784699. The next prime is 81630784747. The reversal of 81630784726 is 62748703618.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20407696180 + ... + 20407696183.

It is an arithmetic number, because the mean of its divisors is an integer number (30611544273).

Almost surely, 2^81630784726 is an apocalyptic number.

81630784726 is a deficient number, since it is larger than the sum of its proper divisors (40815392366).

81630784726 is a wasteful number, since it uses less digits than its factorization.

81630784726 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40815392365.

The product of its (nonzero) digits is 2709504, while the sum is 52.

The spelling of 81630784726 in words is "eighty-one billion, six hundred thirty million, seven hundred eighty-four thousand, seven hundred twenty-six".