27790978 has 4 divisors (see below), whose sum is σ = 41686470. Its totient is φ = 13895488.

The previous prime is 27790963. The next prime is 27790979. The reversal of 27790978 is 87909772.

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., 27699169 + 91809 = 5263^2 + 303^2 .

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 not an unprimeable number, because it can be changed into a prime (27790979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6947743 + ... + 6947746.

Almost surely, 2^27790978 is an apocalyptic number.

27790978 is a deficient number, since it is larger than the sum of its proper divisors (13895492).

27790978 is a wasteful number, since it uses less digits than its factorization.

27790978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13895491.

The product of its (nonzero) digits is 444528, while the sum is 49.

The square root of 27790978 is about 5271.7149012442. The cubic root of 27790978 is about 302.9013973329.

The spelling of 27790978 in words is "twenty-seven million, seven hundred ninety thousand, nine hundred seventy-eight".