28412381 has 4 divisors (see below), whose sum is σ = 28663932. Its totient is φ = 28160832.

The previous prime is 28412369. The next prime is 28412387. The reversal of 28412381 is 18321482.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18321482 = 2 ⋅9160741.

It can be written as a sum of positive squares in 2 ways, for example, as 586756 + 27825625 = 766^2 + 5275^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28412381 is a prime.

It is a super-2 number, since 2×28412381² = 1614526788178322, 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 (28412387) 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, 125606 + ... + 125831.

It is an arithmetic number, because the mean of its divisors is an integer number (7165983).

Almost surely, 2^28412381 is an apocalyptic number.

It is an amenable number.

28412381 is a deficient number, since it is larger than the sum of its proper divisors (251551).

28412381 is a wasteful number, since it uses less digits than its factorization.

28412381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251550.

The product of its digits is 3072, while the sum is 29.

The square root of 28412381 is about 5330.3265378399. The cubic root of 28412381 is about 305.1423898436.

The spelling of 28412381 in words is "twenty-eight million, four hundred twelve thousand, three hundred eighty-one".