28381071 has 16 divisors (see below), whose sum is σ = 38457344. Its totient is φ = 18615744.

The previous prime is 28381069. The next prime is 28381081. The reversal of 28381071 is 17018382.

It is a happy number.

It is not a de Polignac number, because 28381071 - 2¹ = 28381069 is a prime.

It is a super-2 number, since 2×28381071² = 1610970382214082, 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 (28381021) 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, 61875 + ... + 62331.

It is an arithmetic number, because the mean of its divisors is an integer number (2403584).

Almost surely, 2^28381071 is an apocalyptic number.

28381071 is a deficient number, since it is larger than the sum of its proper divisors (10076273).

28381071 is a wasteful number, since it uses less digits than its factorization.

28381071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 750.

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 28381071 is about 5327.3887599836. The cubic root of 28381071 is about 305.0302612633.

It can be divided in two parts, 283810 and 71, that added together give a triangular number (283881 = T₇₅₃).

The spelling of 28381071 in words is "twenty-eight million, three hundred eighty-one thousand, seventy-one".