28181042 has 4 divisors (see below), whose sum is σ = 42271566. Its totient is φ = 14090520.

The previous prime is 28181017. The next prime is 28181051. The reversal of 28181042 is 24018182.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24018182 = 2 ⋅12009091.

It can be written as a sum of positive squares in only one way, i.e., 25897921 + 2283121 = 5089^2 + 1511^2 .

It is a super-2 number, since 2×28181042² = 1588342256411528, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7045259 + ... + 7045262.

Almost surely, 2^28181042 is an apocalyptic number.

28181042 is a deficient number, since it is larger than the sum of its proper divisors (14090524).

28181042 is a wasteful number, since it uses less digits than its factorization.

28181042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14090523.

The product of its (nonzero) digits is 1024, while the sum is 26.

The square root of 28181042 is about 5308.5819198728. The cubic root of 28181042 is about 304.3119561435.

The spelling of 28181042 in words is "twenty-eight million, one hundred eighty-one thousand, forty-two".