28261920 has 96 divisors (see below), whose sum is σ = 90091008. Its totient is φ = 7446528.

The previous prime is 28261913. The next prime is 28261927. The reversal of 28261920 is 2916282.

It is an interprime number because it is at equal distance from previous prime (28261913) and next prime (28261927).

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×28261920² = 1597472244172800, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (28261927) by changing a digit.

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, 46257 + ... + 46863.

It is an arithmetic number, because the mean of its divisors is an integer number (938448).

Almost surely, 2^28261920 is an apocalyptic number.

28261920 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 28261920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45045504).

28261920 is an abundant number, since it is smaller than the sum of its proper divisors (61829088).

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

28261920 is a wasteful number, since it uses less digits than its factorization.

28261920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 722 (or 714 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 28261920 is about 5316.1941273810. The cubic root of 28261920 is about 304.6027974675.

The spelling of 28261920 in words is "twenty-eight million, two hundred sixty-one thousand, nine hundred twenty".