28102997 has 4 divisors (see below), whose sum is σ = 30264780. Its totient is φ = 25941216.

The previous prime is 28102973. The next prime is 28103003. The reversal of 28102997 is 79920182.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79920182 = 2 ⋅39960091.

It can be written as a sum of positive squares in 2 ways, for example, as 10201636 + 17901361 = 3194^2 + 4231^2 .

It is a cyclic number.

It is not a de Polignac number, because 28102997 - 2⁶ = 28102933 is a prime.

It is a super-3 number, since 3×28102997³ (a number of 23 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28102997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28102967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1080872 + ... + 1080897.

It is an arithmetic number, because the mean of its divisors is an integer number (7566195).

Almost surely, 2^28102997 is an apocalyptic number.

It is an amenable number.

28102997 is a deficient number, since it is larger than the sum of its proper divisors (2161783).

28102997 is a wasteful number, since it uses less digits than its factorization.

28102997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2161782.

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 28102997 is about 5301.2259902781. The cubic root of 28102997 is about 304.0307743834.

The spelling of 28102997 in words is "twenty-eight million, one hundred two thousand, nine hundred ninety-seven".