28253997 has 6 divisors (see below), whose sum is σ = 40811342. Its totient is φ = 18835992.

The previous prime is 28253987. The next prime is 28254001. The reversal of 28253997 is 79935282.

28253997 is a `hidden beast` number, since 28 + 2 + 539 + 97 = 666.

It can be written as a sum of positive squares in only one way, i.e., 18198756 + 10055241 = 4266^2 + 3171^2 .

It is not a de Polignac number, because 28253997 - 2⁶ = 28253933 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28253987) 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, 1569658 + ... + 1569675.

Almost surely, 2^28253997 is an apocalyptic number.

It is an amenable number.

28253997 is a deficient number, since it is larger than the sum of its proper divisors (12557345).

28253997 is a wasteful number, since it uses less digits than its factorization.

28253997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3139339 (or 3139336 counting only the distinct ones).

The product of its digits is 272160, while the sum is 45.

The square root of 28253997 is about 5315.4488991994. The cubic root of 28253997 is about 304.5743304995.

The spelling of 28253997 in words is "twenty-eight million, two hundred fifty-three thousand, nine hundred ninety-seven".