28993378 has 4 divisors (see below), whose sum is σ = 43490070. Its totient is φ = 14496688.

The previous prime is 28993357. The next prime is 28993399. The reversal of 28993378 is 87339982.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (28993357) and next prime (28993399).

It can be written as a sum of positive squares in only one way, i.e., 27321529 + 1671849 = 5227^2 + 1293^2 .

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7248343 + ... + 7248346.

Almost surely, 2^28993378 is an apocalyptic number.

28993378 is a deficient number, since it is larger than the sum of its proper divisors (14496692).

28993378 is a wasteful number, since it uses less digits than its factorization.

28993378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14496691.

The product of its digits is 653184, while the sum is 49.

The square root of 28993378 is about 5384.5499347671. The cubic root of 28993378 is about 307.2082958666.

The spelling of 28993378 in words is "twenty-eight million, nine hundred ninety-three thousand, three hundred seventy-eight".