28158789 has 4 divisors (see below), whose sum is σ = 37545056. Its totient is φ = 18772524.

The previous prime is 28158787. The next prime is 28158811. The reversal of 28158789 is 98785182.

28158789 = T₂₄₉₇ + T₂₄₉₈ + ... + T₂₅₀₅.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 28158789 - 2¹ = 28158787 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28158787) 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, 4693129 + ... + 4693134.

It is an arithmetic number, because the mean of its divisors is an integer number (9386264).

Almost surely, 2^28158789 is an apocalyptic number.

It is an amenable number.

28158789 is a deficient number, since it is larger than the sum of its proper divisors (9386267).

28158789 is an equidigital number, since it uses as much as digits as its factorization.

28158789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9386266.

The product of its digits is 322560, while the sum is 48.

The square root of 28158789 is about 5306.4855601424. The cubic root of 28158789 is about 304.2318356474.

The spelling of 28158789 in words is "twenty-eight million, one hundred fifty-eight thousand, seven hundred eighty-nine".