28619640 has 192 divisors, whose sum is σ = 109287360. Its totient is φ = 6359040.

The previous prime is 28619627. The next prime is 28619677. The reversal of 28619640 is 4691682.

28619640 is a `hidden beast` number, since 2 + 8 + 6 + 1 + 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 = 28619595 and 28619604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 103182 + ... + 103458.

It is an arithmetic number, because the mean of its divisors is an integer number (569205).

Almost surely, 2^28619640 is an apocalyptic number.

28619640 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 28619640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (54643680).

28619640 is an abundant number, since it is smaller than the sum of its proper divisors (80667720).

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

28619640 is a wasteful number, since it uses less digits than its factorization.

28619640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342 (or 335 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 28619640 is about 5349.7327036031. The cubic root of 28619640 is about 305.8825641894.

The spelling of 28619640 in words is "twenty-eight million, six hundred nineteen thousand, six hundred forty".