28028005501 has 4 divisors (see below), whose sum is σ = 28132199100. Its totient is φ = 27923811904.

The previous prime is 28028005471. The next prime is 28028005507. The reversal of 28028005501 is 10550082082.

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

It can be written as a sum of positive squares in 2 ways, for example, as 12752281476 + 15275724025 = 112926^2 + 123595^2 .

It is a cyclic number.

It is not a de Polignac number, because 28028005501 - 2²¹ = 28025908349 is a prime.

It is a super-2 number, since 2×28028005501² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28028005507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52096396 + ... + 52096933.

It is an arithmetic number, because the mean of its divisors is an integer number (7033049775).

Almost surely, 2^28028005501 is an apocalyptic number.

It is an amenable number.

28028005501 is a deficient number, since it is larger than the sum of its proper divisors (104193599).

28028005501 is a wasteful number, since it uses less digits than its factorization.

28028005501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104193598.

The product of its (nonzero) digits is 6400, while the sum is 31.

Adding to 28028005501 its reverse (10550082082), we get a palindrome (38578087583).

The spelling of 28028005501 in words is "twenty-eight billion, twenty-eight million, five thousand, five hundred one".