28580381 has 4 divisors (see below), whose sum is σ = 28635552. Its totient is φ = 28525212.

The previous prime is 28580359. The next prime is 28580413. The reversal of 28580381 is 18308582.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18308582 = 2 ⋅9154291.

It is a cyclic number.

It is not a de Polignac number, because 28580381 - 2¹⁸ = 28318237 is a prime.

It is a super-2 number, since 2×28580381² = 1633676356210322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28580311) 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, 26801 + ... + 27846.

It is an arithmetic number, because the mean of its divisors is an integer number (7158888).

Almost surely, 2^28580381 is an apocalyptic number.

It is an amenable number.

28580381 is a deficient number, since it is larger than the sum of its proper divisors (55171).

28580381 is an equidigital number, since it uses as much as digits as its factorization.

28580381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55170.

The product of its (nonzero) digits is 15360, while the sum is 35.

The square root of 28580381 is about 5346.0621956726. The cubic root of 28580381 is about 305.7426353535.

The spelling of 28580381 in words is "twenty-eight million, five hundred eighty thousand, three hundred eighty-one".