28907155 has 4 divisors (see below), whose sum is σ = 34688592. Its totient is φ = 23125720.

The previous prime is 28907149. The next prime is 28907183. The reversal of 28907155 is 55170982.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55170982 = 2 ⋅27585491.

It is not a de Polignac number, because 28907155 - 2¹⁹ = 28382867 is a prime.

It is a super-2 number, since 2×28907155² = 1671247220388050, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2890711 + ... + 2890720.

It is an arithmetic number, because the mean of its divisors is an integer number (8672148).

Almost surely, 2^28907155 is an apocalyptic number.

28907155 is a deficient number, since it is larger than the sum of its proper divisors (5781437).

28907155 is an equidigital number, since it uses as much as digits as its factorization.

28907155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5781436.

The product of its (nonzero) digits is 25200, while the sum is 37.

The square root of 28907155 is about 5376.5374545334. The cubic root of 28907155 is about 306.9034593367.

The spelling of 28907155 in words is "twenty-eight million, nine hundred seven thousand, one hundred fifty-five".