28251001001 has 4 divisors (see below), whose sum is σ = 28542248532. Its totient is φ = 27959753472.

The previous prime is 28251000983. The next prime is 28251001007. The reversal of 28251001001 is 10010015282.

It is a happy number.

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 4070440000 + 24180561001 = 63800^2 + 155501^2 .

It is a cyclic number.

It is not a de Polignac number, because 28251001001 - 2⁶ = 28251000937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28251001007) 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, 145623620 + ... + 145623813.

It is an arithmetic number, because the mean of its divisors is an integer number (7135562133).

Almost surely, 2^28251001001 is an apocalyptic number.

It is an amenable number.

28251001001 is a deficient number, since it is larger than the sum of its proper divisors (291247531).

28251001001 is an equidigital number, since it uses as much as digits as its factorization.

28251001001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291247530.

The product of its (nonzero) digits is 160, while the sum is 20.

Adding to 28251001001 its reverse (10010015282), we get a palindrome (38261016283).

The spelling of 28251001001 in words is "twenty-eight billion, two hundred fifty-one million, one thousand, one".