28778738 has 8 divisors (see below), whose sum is σ = 43595820. Its totient is φ = 14246800.

The previous prime is 28778719. The next prime is 28778747. The reversal of 28778738 is 83787782.

It can be written as a sum of positive squares in 2 ways, for example, as 27426169 + 1352569 = 5237^2 + 1163^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71033 + ... + 71436.

Almost surely, 2^28778738 is an apocalyptic number.

28778738 is a deficient number, since it is larger than the sum of its proper divisors (14817082).

28778738 is a wasteful number, since it uses less digits than its factorization.

28778738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142572.

The product of its digits is 1053696, while the sum is 50.

The square root of 28778738 is about 5364.5818103558. The cubic root of 28778738 is about 306.4483225761.

The spelling of 28778738 in words is "twenty-eight million, seven hundred seventy-eight thousand, seven hundred thirty-eight".