8261660791 has 4 divisors (see below), whose sum is σ = 8401689000. Its totient is φ = 8121632584.

The previous prime is 8261660783. The next prime is 8261660809. The reversal of 8261660791 is 1970661628.

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

It is a cyclic number.

It is not a de Polignac number, because 8261660791 - 2³ = 8261660783 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8261660711) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70014016 + ... + 70014133.

It is an arithmetic number, because the mean of its divisors is an integer number (2100422250).

Almost surely, 2^8261660791 is an apocalyptic number.

8261660791 is a deficient number, since it is larger than the sum of its proper divisors (140028209).

8261660791 is a wasteful number, since it uses less digits than its factorization.

8261660791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140028208.

The product of its (nonzero) digits is 217728, while the sum is 46.

The square root of 8261660791 is about 90893.6784985623. The cubic root of 8261660791 is about 2021.5715632506.

The spelling of 8261660791 in words is "eight billion, two hundred sixty-one million, six hundred sixty thousand, seven hundred ninety-one".