28011204691 has 4 divisors (see below), whose sum is σ = 29658922632. Its totient is φ = 26363486752.

The previous prime is 28011204667. The next prime is 28011204701. The reversal of 28011204691 is 19640211082.

It is a happy number.

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 28011204691 - 2¹¹ = 28011202643 is a prime.

It is a super-2 number, since 2×28011204691² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28011202691) 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, 823858945 + ... + 823858978.

It is an arithmetic number, because the mean of its divisors is an integer number (7414730658).

Almost surely, 2^28011204691 is an apocalyptic number.

28011204691 is a deficient number, since it is larger than the sum of its proper divisors (1647717941).

28011204691 is a wasteful number, since it uses less digits than its factorization.

28011204691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1647717940.

The product of its (nonzero) digits is 6912, while the sum is 34.

The spelling of 28011204691 in words is "twenty-eight billion, eleven million, two hundred four thousand, six hundred ninety-one".