28778169 has 8 divisors (see below), whose sum is σ = 43852480. Its totient is φ = 16444656.

The previous prime is 28778111. The next prime is 28778171. The reversal of 28778169 is 96187782.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28778169 - 2¹³ = 28769977 is a prime.

It is a super-2 number, since 2×28778169² = 1656366021985122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28778669) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 685174 + ... + 685215.

It is an arithmetic number, because the mean of its divisors is an integer number (5481560).

Almost surely, 2^28778169 is an apocalyptic number.

It is an amenable number.

28778169 is a deficient number, since it is larger than the sum of its proper divisors (15074311).

28778169 is a wasteful number, since it uses less digits than its factorization.

28778169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1370399.

The product of its digits is 338688, while the sum is 48.

The square root of 28778169 is about 5364.5287770689. The cubic root of 28778169 is about 306.4463029109.

The spelling of 28778169 in words is "twenty-eight million, seven hundred seventy-eight thousand, one hundred sixty-nine".