28155664 has 10 divisors (see below), whose sum is σ = 54551630. Its totient is φ = 14077824.

The previous prime is 28155649. The next prime is 28155671. The reversal of 28155664 is 46655182.

It can be written as a sum of positive squares in only one way, i.e., 18421264 + 9734400 = 4292^2 + 3120^2 .

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 as a sum of consecutive naturals, namely, 879849 + ... + 879880.

It is an arithmetic number, because the mean of its divisors is an integer number (5455163).

Almost surely, 2^28155664 is an apocalyptic number.

It is an amenable number.

28155664 is a deficient number, since it is larger than the sum of its proper divisors (26395966).

28155664 is a wasteful number, since it uses less digits than its factorization.

28155664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1759737 (or 1759731 counting only the distinct ones).

The product of its digits is 57600, while the sum is 37.

The square root of 28155664 is about 5306.1911009688. The cubic root of 28155664 is about 304.2205809061.

It can be divided in two parts, 281 and 55664, that added together give a triangular number (55945 = T₃₃₄).

The spelling of 28155664 in words is "twenty-eight million, one hundred fifty-five thousand, six hundred sixty-four".