28349640 has 96 divisors (see below), whose sum is σ = 100526400. Its totient is φ = 6871680.

The previous prime is 28349611. The next prime is 28349663. The reversal of 28349640 is 4694382.

It is a happy number.

28349640 is a `hidden beast` number, since 2 + 8 + 3 + 4 + 9 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 28349595 and 28349604.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 381 + ... + 7539.

It is an arithmetic number, because the mean of its divisors is an integer number (1047150).

Almost surely, 2^28349640 is an apocalyptic number.

28349640 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 28349640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50263200).

28349640 is an abundant number, since it is smaller than the sum of its proper divisors (72176760).

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

28349640 is a wasteful number, since it uses less digits than its factorization.

28349640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7187 (or 7180 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 28349640 is about 5324.4379985121. The cubic root of 28349640 is about 304.9176163770.

The spelling of 28349640 in words is "twenty-eight million, three hundred forty-nine thousand, six hundred forty".