28920697 has 4 divisors (see below), whose sum is σ = 31145380. Its totient is φ = 26696016.

The previous prime is 28920677. The next prime is 28920707. The reversal of 28920697 is 79602982.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79602982 = 2 ⋅39801491.

It can be written as a sum of positive squares in 2 ways, for example, as 4822416 + 24098281 = 2196^2 + 4909^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28920697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28920607) 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, 1112322 + ... + 1112347.

It is an arithmetic number, because the mean of its divisors is an integer number (7786345).

Almost surely, 2^28920697 is an apocalyptic number.

It is an amenable number.

28920697 is a deficient number, since it is larger than the sum of its proper divisors (2224683).

28920697 is a wasteful number, since it uses less digits than its factorization.

28920697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2224682.

The product of its (nonzero) digits is 108864, while the sum is 43.

The square root of 28920697 is about 5377.7966677813. The cubic root of 28920697 is about 306.9513763988.

The spelling of 28920697 in words is "twenty-eight million, nine hundred twenty thousand, six hundred ninety-seven".