28906840 has 32 divisors (see below), whose sum is σ = 65468880. Its totient is φ = 11486592.

The previous prime is 28906831. The next prime is 28906877. The reversal of 28906840 is 4860982.

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 28906840.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3979 + ... + 8581.

Almost surely, 2^28906840 is an apocalyptic number.

28906840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28906840 is an abundant number, since it is smaller than the sum of its proper divisors (36562040).

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

28906840 is a wasteful number, since it uses less digits than its factorization.

28906840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4771 (or 4767 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 37.

The square root of 28906840 is about 5376.5081605072. The cubic root of 28906840 is about 306.9023445615.

It can be divided in two parts, 2890 and 6840, that added together give a triangular number (9730 = T₁₃₉).

The spelling of 28906840 in words is "twenty-eight million, nine hundred six thousand, eight hundred forty".