28778390 has 8 divisors (see below), whose sum is σ = 51801120. Its totient is φ = 11511352.

The previous prime is 28778389. The next prime is 28778419. The reversal of 28778390 is 9387782.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1438910 + ... + 1438929.

It is an arithmetic number, because the mean of its divisors is an integer number (6475140).

Almost surely, 2^28778390 is an apocalyptic number.

28778390 is a deficient number, since it is larger than the sum of its proper divisors (23022730).

28778390 is a wasteful number, since it uses less digits than its factorization.

28778390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2877846.

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

The square root of 28778390 is about 5364.5493752971. The cubic root of 28778390 is about 306.4470873534.

The spelling of 28778390 in words is "twenty-eight million, seven hundred seventy-eight thousand, three hundred ninety".