28291940 has 12 divisors (see below), whose sum is σ = 59413116. Its totient is φ = 11316768.

The previous prime is 28291897. The next prime is 28291973. The reversal of 28291940 is 4919282.

It can be written as a sum of positive squares in 2 ways, for example, as 10719076 + 17572864 = 3274^2 + 4192^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 28291940.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 707279 + ... + 707318.

It is an arithmetic number, because the mean of its divisors is an integer number (4951093).

Almost surely, 2^28291940 is an apocalyptic number.

28291940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28291940 is an abundant number, since it is smaller than the sum of its proper divisors (31121176).

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

28291940 is a wasteful number, since it uses less digits than its factorization.

28291940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1414606 (or 1414604 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 28291940 is about 5319.0168264445. The cubic root of 28291940 is about 304.7106096782.

The spelling of 28291940 in words is "twenty-eight million, two hundred ninety-one thousand, nine hundred forty".