28783980 has 36 divisors (see below), whose sum is σ = 87311952. Its totient is φ = 7675680.

The previous prime is 28783967. The next prime is 28783991. The reversal of 28783980 is 8938782.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 79776 + ... + 80135.

It is an arithmetic number, because the mean of its divisors is an integer number (2425332).

Almost surely, 2^28783980 is an apocalyptic number.

28783980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28783980 is an abundant number, since it is smaller than the sum of its proper divisors (58527972).

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

28783980 is a wasteful number, since it uses less digits than its factorization.

28783980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159926 (or 159921 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The square root of 28783980 is about 5365.0703630055. The cubic root of 28783980 is about 306.4669277998.

The spelling of 28783980 in words is "twenty-eight million, seven hundred eighty-three thousand, nine hundred eighty".