28617993 has 12 divisors (see below), whose sum is σ = 41549508. Its totient is φ = 18980640.

The previous prime is 28617977. The next prime is 28617997. The reversal of 28617993 is 39971682.

28617993 is a `hidden beast` number, since 28 + 617 + 9 + 9 + 3 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 21790224 + 6827769 = 4668^2 + 2613^2 .

It is not a de Polignac number, because 28617993 - 2⁴ = 28617977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28617997) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6298 + ... + 9843.

It is an arithmetic number, because the mean of its divisors is an integer number (3462459).

Almost surely, 2^28617993 is an apocalyptic number.

It is an amenable number.

28617993 is a deficient number, since it is larger than the sum of its proper divisors (12931515).

28617993 is a wasteful number, since it uses less digits than its factorization.

28617993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16344 (or 16341 counting only the distinct ones).

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

The square root of 28617993 is about 5349.5787684639. The cubic root of 28617993 is about 305.8766964444.

The spelling of 28617993 in words is "twenty-eight million, six hundred seventeen thousand, nine hundred ninety-three".