28881780 has 24 divisors (see below), whose sum is σ = 80869152. Its totient is φ = 7701792.

The previous prime is 28881773. The next prime is 28881791. The reversal of 28881780 is 8718882.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 240622 + ... + 240741.

It is an arithmetic number, because the mean of its divisors is an integer number (3369548).

Almost surely, 2^28881780 is an apocalyptic number.

28881780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28881780 is an abundant number, since it is smaller than the sum of its proper divisors (51987372).

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

28881780 is a wasteful number, since it uses less digits than its factorization.

28881780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481375 (or 481373 counting only the distinct ones).

The product of its (nonzero) digits is 57344, while the sum is 42.

The square root of 28881780 is about 5374.1771463174. The cubic root of 28881780 is about 306.8136320363.

The spelling of 28881780 in words is "twenty-eight million, eight hundred eighty-one thousand, seven hundred eighty".