28152281 has 16 divisors (see below), whose sum is σ = 30844800. Its totient is φ = 25603200.

The previous prime is 28152277. The next prime is 28152287. The reversal of 28152281 is 18225182.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 28152281 - 2² = 28152277 is a prime.

It is a super-2 number, since 2×28152281² = 1585101851005922, which contains 22 as substring.

It is a Duffinian number.

Its product of digits (2560) is a multiple of the sum of its prime divisors (640).

It is not an unprimeable number, because it can be changed into a prime (28152287) 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, 55055 + ... + 55563.

It is an arithmetic number, because the mean of its divisors is an integer number (1927800).

Almost surely, 2^28152281 is an apocalyptic number.

It is an amenable number.

28152281 is a deficient number, since it is larger than the sum of its proper divisors (2692519).

28152281 is a wasteful number, since it uses less digits than its factorization.

28152281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 640.

The product of its digits is 2560, while the sum is 29.

The square root of 28152281 is about 5305.8723128247. The cubic root of 28152281 is about 304.2083960345.

The spelling of 28152281 in words is "twenty-eight million, one hundred fifty-two thousand, two hundred eighty-one".