28477978 has 4 divisors (see below), whose sum is σ = 42716970. Its totient is φ = 14238988.

The previous prime is 28477963. The next prime is 28478003. The reversal of 28477978 is 87977482.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 20766249 + 7711729 = 4557^2 + 2777^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7119493 + ... + 7119496.

Almost surely, 2^28477978 is an apocalyptic number.

28477978 is a deficient number, since it is larger than the sum of its proper divisors (14238992).

28477978 is a wasteful number, since it uses less digits than its factorization.

28477978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14238991.

The product of its digits is 1580544, while the sum is 52.

The square root of 28477978 is about 5336.4761781535. The cubic root of 28477978 is about 305.3770415469.

The spelling of 28477978 in words is "twenty-eight million, four hundred seventy-seven thousand, nine hundred seventy-eight".