28085510921 has 16 divisors (see below), whose sum is σ = 30351619200. Its totient is φ = 25834647168.

The previous prime is 28085510917. The next prime is 28085510941. The reversal of 28085510921 is 12901558082.

It is a cyclic number.

It is not a de Polignac number, because 28085510921 - 2² = 28085510917 is a prime.

It is a super-2 number, since 2×28085510921² (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 (28085510941) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6147380 + ... + 6151946.

It is an arithmetic number, because the mean of its divisors is an integer number (1896976200).

Almost surely, 2^28085510921 is an apocalyptic number.

It is an amenable number.

28085510921 is a deficient number, since it is larger than the sum of its proper divisors (2266108279).

28085510921 is a wasteful number, since it uses less digits than its factorization.

28085510921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6128.

The product of its (nonzero) digits is 57600, while the sum is 41.

The spelling of 28085510921 in words is "twenty-eight billion, eighty-five million, five hundred ten thousand, nine hundred twenty-one".