247978 has 4 divisors (see below), whose sum is σ = 371970. Its totient is φ = 123988.

The previous prime is 247957. The next prime is 247991. The reversal of 247978 is 879742.

It is a happy number.

247978 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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., 227529 + 20449 = 477^2 + 143^2 .

It is a super-2 number, since 2×247978² = 122986176968, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61993 + ... + 61996.

2²⁴⁷⁹⁷⁸ is an apocalyptic number.

247978 is a deficient number, since it is larger than the sum of its proper divisors (123992).

247978 is a wasteful number, since it uses less digits than its factorization.

247978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123991.

The product of its digits is 28224, while the sum is 37.

The square root of 247978 is about 497.9738948981. The cubic root of 247978 is about 62.8257551871.

It can be divided in two parts, 247 and 978, that added together give a triangular number (1225 = T₄₉).

The spelling of 247978 in words is "two hundred forty-seven thousand, nine hundred seventy-eight".