8261215643128 has 64 divisors (see below), whose sum is σ = 17766454749120. Its totient is φ = 3527766528000.

The previous prime is 8261215643111. The next prime is 8261215643143. The reversal of 8261215643128 is 8213465121628.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25557558 + ... + 25878778.

It is an arithmetic number, because the mean of its divisors is an integer number (277600855455).

Almost surely, 2^{8261215643128} is an apocalyptic number.

It is an amenable number.

8261215643128 is an abundant number, since it is smaller than the sum of its proper divisors (9505239105992).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

8261215643128 is a wasteful number, since it uses less digits than its factorization.

8261215643128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322888 (or 322884 counting only the distinct ones).

The product of its digits is 1105920, while the sum is 49.

The spelling of 8261215643128 in words is "eight trillion, two hundred sixty-one billion, two hundred fifteen million, six hundred forty-three thousand, one hundred twenty-eight".