28198621 has 16 divisors (see below), whose sum is σ = 32306688. Its totient is φ = 24362800.

The previous prime is 28198609. The next prime is 28198633. The reversal of 28198621 is 12689182.

It is an interprime number because it is at equal distance from previous prime (28198609) and next prime (28198633).

It is not a de Polignac number, because 28198621 - 2⁵ = 28198589 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 (28198601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57186 + ... + 57676.

It is an arithmetic number, because the mean of its divisors is an integer number (2019168).

Almost surely, 2^28198621 is an apocalyptic number.

It is an amenable number.

28198621 is a deficient number, since it is larger than the sum of its proper divisors (4108067).

28198621 is a wasteful number, since it uses less digits than its factorization.

28198621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 752.

The product of its digits is 13824, while the sum is 37.

The square root of 28198621 is about 5310.2373769917. The cubic root of 28198621 is about 304.3752183884.

The spelling of 28198621 in words is "twenty-eight million, one hundred ninety-eight thousand, six hundred twenty-one".