28913778 has 12 divisors (see below), whose sum is σ = 62646558. Its totient is φ = 9637920.

The previous prime is 28913749. The next prime is 28913791. The reversal of 28913778 is 87731982.

It can be written as a sum of positive squares in only one way, i.e., 25979409 + 2934369 = 5097^2 + 1713^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 803143 + ... + 803178.

Almost surely, 2^28913778 is an apocalyptic number.

28913778 is an abundant number, since it is smaller than the sum of its proper divisors (33732780).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28913778 is a wasteful number, since it uses less digits than its factorization.

28913778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1606329 (or 1606326 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 28913778 is about 5377.1533361064. The cubic root of 28913778 is about 306.9268960533.

The spelling of 28913778 in words is "twenty-eight million, nine hundred thirteen thousand, seven hundred seventy-eight".