28750000 has 80 divisors (see below), whose sum is σ = 72656064. Its totient is φ = 11000000.

The previous prime is 28749967. The next prime is 28750019. The reversal of 28750000 is 5782.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1249989 + ... + 1250011.

Almost surely, 2^28750000 is an apocalyptic number.

28750000 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 28750000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36328032).

28750000 is an abundant number, since it is smaller than the sum of its proper divisors (43906064).

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

28750000 is an frugal number, since it uses more digits than its factorization.

28750000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66 (or 30 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 28750000 is about 5361.9026473818. The cubic root of 28750000 is about 306.3462837614.

Adding to 28750000 its reverse (5782), we get a palindrome (28755782).

The spelling of 28750000 in words is "twenty-eight million, seven hundred fifty thousand".