81502502678 has 4 divisors (see below), whose sum is σ = 122253754020. Its totient is φ = 40751251338.

The previous prime is 81502502663. The next prime is 81502502699. The reversal of 81502502678 is 87620520518.

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 polite number, since it can be written as a sum of consecutive naturals, namely, 20375625668 + ... + 20375625671.

It is an arithmetic number, because the mean of its divisors is an integer number (30563438505).

Almost surely, 2^81502502678 is an apocalyptic number.

81502502678 is a deficient number, since it is larger than the sum of its proper divisors (40751251342).

81502502678 is a wasteful number, since it uses less digits than its factorization.

81502502678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40751251341.

The product of its (nonzero) digits is 268800, while the sum is 44.

The spelling of 81502502678 in words is "eighty-one billion, five hundred two million, five hundred two thousand, six hundred seventy-eight".