28897733 has 6 divisors (see below), whose sum is σ = 29120454. Its totient is φ = 28675976.

The previous prime is 28897721. The next prime is 28897741. The reversal of 28897733 is 33779882.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 28751044 + 146689 = 5362^2 + 383^2 .

It is a de Polignac number, because none of the positive numbers 2^k-28897733 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28897793) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 75260 + ... + 75642.

It is an arithmetic number, because the mean of its divisors is an integer number (4853409).

Almost surely, 2^28897733 is an apocalyptic number.

It is an amenable number.

28897733 is a deficient number, since it is larger than the sum of its proper divisors (222721).

28897733 is an frugal number, since it uses more digits than its factorization.

28897733 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 963 (or 580 counting only the distinct ones).

The product of its digits is 508032, while the sum is 47.

The square root of 28897733 is about 5375.6611686378. The cubic root of 28897733 is about 306.8701116688.

The spelling of 28897733 in words is "twenty-eight million, eight hundred ninety-seven thousand, seven hundred thirty-three".