28331001 has 6 divisors (see below), whose sum is σ = 40922570. Its totient is φ = 18887328.

The previous prime is 28330997. The next prime is 28331003. The reversal of 28331001 is 10013382.

It can be written as a sum of positive squares in only one way, i.e., 28100601 + 230400 = 5301^2 + 480^2 .

It is not a de Polignac number, because 28331001 - 2² = 28330997 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28331003) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1573936 + ... + 1573953.

Almost surely, 2^28331001 is an apocalyptic number.

It is an amenable number.

28331001 is a deficient number, since it is larger than the sum of its proper divisors (12591569).

28331001 is a wasteful number, since it uses less digits than its factorization.

28331001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3147895 (or 3147892 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 28331001 is about 5322.6873851467. The cubic root of 28331001 is about 304.8507771337.

Adding to 28331001 its reverse (10013382), we get a palindrome (38344383).

The spelling of 28331001 in words is "twenty-eight million, three hundred thirty-one thousand, one".