28881577 has 4 divisors (see below), whose sum is σ = 30401680. Its totient is φ = 27361476.

The previous prime is 28881569. The next prime is 28881617. The reversal of 28881577 is 77518882.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28881577 - 2³ = 28881569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28881527) by changing a digit.

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, 760023 + ... + 760060.

It is an arithmetic number, because the mean of its divisors is an integer number (7600420).

Almost surely, 2^28881577 is an apocalyptic number.

It is an amenable number.

28881577 is a deficient number, since it is larger than the sum of its proper divisors (1520103).

28881577 is a wasteful number, since it uses less digits than its factorization.

28881577 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1520102.

The product of its digits is 250880, while the sum is 46.

The square root of 28881577 is about 5374.1582596719. The cubic root of 28881577 is about 306.8129132058.

It can be divided in two parts, 2888 and 1577, that added together give a triangular number (4465 = T₉₄).

The spelling of 28881577 in words is "twenty-eight million, eight hundred eighty-one thousand, five hundred seventy-seven".