28145724 has 12 divisors (see below), whose sum is σ = 65673384. Its totient is φ = 9381904.

The previous prime is 28145723. The next prime is 28145791. The reversal of 28145724 is 42754182.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28145723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1172727 + ... + 1172750.

It is an arithmetic number, because the mean of its divisors is an integer number (5472782).

Almost surely, 2^28145724 is an apocalyptic number.

It is an amenable number.

28145724 is an abundant number, since it is smaller than the sum of its proper divisors (37527660).

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

28145724 is a wasteful number, since it uses less digits than its factorization.

28145724 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2345484 (or 2345482 counting only the distinct ones).

The product of its digits is 17920, while the sum is 33.

The square root of 28145724 is about 5305.2543765591. The cubic root of 28145724 is about 304.1847762867.

The spelling of 28145724 in words is "twenty-eight million, one hundred forty-five thousand, seven hundred twenty-four".