28015880 has 64 divisors (see below), whose sum is σ = 67046400. Its totient is φ = 10506240.

The previous prime is 28015843. The next prime is 28015907. The reversal of 28015880 is 8851082.

28015880 = T₇₂₀ + T₇₂₁ + ... + T₈₁₄.

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 15 ways as a sum of consecutive naturals, for example, 145064 + ... + 145256.

It is an arithmetic number, because the mean of its divisors is an integer number (1047600).

Almost surely, 2^28015880 is an apocalyptic number.

28015880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28015880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33523200).

28015880 is an abundant number, since it is smaller than the sum of its proper divisors (39030520).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28015880 is a wasteful number, since it uses less digits than its factorization.

28015880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 414 (or 410 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 32.

The square root of 28015880 is about 5293.0029283952. The cubic root of 28015880 is about 303.7162923300.

The spelling of 28015880 in words is "twenty-eight million, fifteen thousand, eight hundred eighty".