28208131 has 16 divisors (see below), whose sum is σ = 33352704. Its totient is φ = 23356224.

The previous prime is 28208113. The next prime is 28208153. The reversal of 28208131 is 13180282.

28208131 = T₄₉₈ + T₄₉₉ + ... + T₆₆₃.

It is a cyclic number.

It is not a de Polignac number, because 28208131 - 2¹¹ = 28206083 is a prime.

It is a super-2 number, since 2×28208131² = 1591397309026322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28208096 and 28208105.

It is not an unprimeable number, because it can be changed into a prime (28208101) 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, 26791 + ... + 27823.

It is an arithmetic number, because the mean of its divisors is an integer number (2084544).

Almost surely, 2^28208131 is an apocalyptic number.

28208131 is a deficient number, since it is larger than the sum of its proper divisors (5144573).

28208131 is a wasteful number, since it uses less digits than its factorization.

28208131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1170.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 28208131 is about 5311.1327417040. The cubic root of 28208131 is about 304.4094314443.

The spelling of 28208131 in words is "twenty-eight million, two hundred eight thousand, one hundred thirty-one".