28397961 has 6 divisors (see below), whose sum is σ = 41019290. Its totient is φ = 18931968.

The previous prime is 28397947. The next prime is 28397969. The reversal of 28397961 is 16979382.

It can be written as a sum of positive squares in only one way, i.e., 25401600 + 2996361 = 5040^2 + 1731^2 .

It is not a de Polignac number, because 28397961 - 2⁹ = 28397449 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28397969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1577656 + ... + 1577673.

Almost surely, 2^28397961 is an apocalyptic number.

It is an amenable number.

28397961 is a deficient number, since it is larger than the sum of its proper divisors (12621329).

28397961 is a wasteful number, since it uses less digits than its factorization.

28397961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3155335 (or 3155332 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 28397961 is about 5328.9737285898. The cubic root of 28397961 is about 305.0907586214.

The spelling of 28397961 in words is "twenty-eight million, three hundred ninety-seven thousand, nine hundred sixty-one".