821728078611 has 8 divisors (see below), whose sum is σ = 1195240841664. Its totient is φ = 498017017320.

The previous prime is 821728078607. The next prime is 821728078673. The reversal of 821728078611 is 116870827128.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 821728078611 - 2² = 821728078607 is a prime.

It is not an unprimeable number, because it can be changed into a prime (821728078511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12450425401 + ... + 12450425466.

It is an arithmetic number, because the mean of its divisors is an integer number (149405105208).

Almost surely, 2^821728078611 is an apocalyptic number.

821728078611 is a deficient number, since it is larger than the sum of its proper divisors (373512763053).

821728078611 is a wasteful number, since it uses less digits than its factorization.

821728078611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24900850881.

The product of its (nonzero) digits is 602112, while the sum is 51.

The spelling of 821728078611 in words is "eight hundred twenty-one billion, seven hundred twenty-eight million, seventy-eight thousand, six hundred eleven".