28911625 has 8 divisors (see below), whose sum is σ = 36081864. Its totient is φ = 23129200.

The previous prime is 28911599. The next prime is 28911629. The reversal of 28911625 is 52611982.

It can be written as a sum of positive squares in 4 ways, for example, as 139129 + 28772496 = 373^2 + 5364^2 .

It is a de Polignac number, because none of the positive numbers 2^k-28911625 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28911629) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 115522 + ... + 115771.

It is an arithmetic number, because the mean of its divisors is an integer number (4510233).

Almost surely, 2^28911625 is an apocalyptic number.

28911625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28911625 is a deficient number, since it is larger than the sum of its proper divisors (7170239).

28911625 is an equidigital number, since it uses as much as digits as its factorization.

28911625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 231308 (or 231298 counting only the distinct ones).

The product of its digits is 8640, while the sum is 34.

The square root of 28911625 is about 5376.9531335134. The cubic root of 28911625 is about 306.9192776553.

The spelling of 28911625 in words is "twenty-eight million, nine hundred eleven thousand, six hundred twenty-five".