28040700 has 72 divisors (see below), whose sum is σ = 81800320. Its totient is φ = 7416000.

The previous prime is 28040699. The next prime is 28040729. The reversal of 28040700 is 704082.

It is a happy number.

It is a congruent number.

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, 44991 + ... + 45609.

Almost surely, 2^28040700 is an apocalyptic number.

28040700 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 28040700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40900160).

28040700 is an abundant number, since it is smaller than the sum of its proper divisors (53759620).

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

28040700 is a wasteful number, since it uses less digits than its factorization.

28040700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 787 (or 780 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 21.

The square root of 28040700 is about 5295.3470141248. The cubic root of 28040700 is about 303.8059559228.

Adding to 28040700 its reverse (704082), we get a palindrome (28744782).

The spelling of 28040700 in words is "twenty-eight million, forty thousand, seven hundred".