79905911643 has 32 divisors (see below), whose sum is σ = 128629299200. Its totient is φ = 48838917600.

The previous prime is 79905911623. The next prime is 79905911653. The reversal of 79905911643 is 34611950997.

79905911643 is a `hidden beast` number, since 7 + 9 + 9 + 0 + 591 + 1 + 6 + 43 = 666.

It is not a de Polignac number, because 79905911643 - 2⁵ = 79905911611 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 79905911643.

It is not an unprimeable number, because it can be changed into a prime (79905911623) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2496388 + ... + 2528193.

It is an arithmetic number, because the mean of its divisors is an integer number (4019665600).

Almost surely, 2^79905911643 is an apocalyptic number.

79905911643 is a deficient number, since it is larger than the sum of its proper divisors (48723387557).

79905911643 is a wasteful number, since it uses less digits than its factorization.

79905911643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5024640 (or 5024634 counting only the distinct ones).

The product of its (nonzero) digits is 1837080, while the sum is 54.

The spelling of 79905911643 in words is "seventy-nine billion, nine hundred five million, nine hundred eleven thousand, six hundred forty-three".