28461720 has 128 divisors (see below), whose sum is σ = 100823040. Its totient is φ = 6289920.

The previous prime is 28461703. The next prime is 28461733. The reversal of 28461720 is 2716482.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 25494 + ... + 26586.

It is an arithmetic number, because the mean of its divisors is an integer number (787680).

Almost surely, 2^28461720 is an apocalyptic number.

28461720 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 28461720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50411520).

28461720 is an abundant number, since it is smaller than the sum of its proper divisors (72361320).

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

28461720 is a wasteful number, since it uses less digits than its factorization.

28461720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1145 (or 1141 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 28461720 is about 5334.9526708304. The cubic root of 28461720 is about 305.3189175111.

The spelling of 28461720 in words is "twenty-eight million, four hundred sixty-one thousand, seven hundred twenty".