28770389 has 4 divisors (see below), whose sum is σ = 30284640. Its totient is φ = 27256140.

The previous prime is 28770383. The next prime is 28770421. The reversal of 28770389 is 98307782.

It is a happy number.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28770389 is a prime.

It is a super-2 number, since 2×28770389² = 1655470566422642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28770383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 757097 + ... + 757134.

It is an arithmetic number, because the mean of its divisors is an integer number (7571160).

Almost surely, 2^28770389 is an apocalyptic number.

It is an amenable number.

28770389 is a deficient number, since it is larger than the sum of its proper divisors (1514251).

28770389 is a wasteful number, since it uses less digits than its factorization.

28770389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1514250.

The product of its (nonzero) digits is 169344, while the sum is 44.

The square root of 28770389 is about 5363.8035944654. The cubic root of 28770389 is about 306.4186851344.

The spelling of 28770389 in words is "twenty-eight million, seven hundred seventy thousand, three hundred eighty-nine".