5491978 has 4 divisors (see below), whose sum is σ = 8237970. Its totient is φ = 2745988.

The previous prime is 5491973. The next prime is 5491979. The reversal of 5491978 is 8791945.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8791945 = 5 ⋅1758389.

It can be written as a sum of positive squares in only one way, i.e., 4297329 + 1194649 = 2073^2 + 1093^2 .

It is not an unprimeable number, because it can be changed into a prime (5491973) by changing a digit.

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, 1372993 + ... + 1372996.

Almost surely, 2^5491978 is an apocalyptic number.

5491978 is a deficient number, since it is larger than the sum of its proper divisors (2745992).

5491978 is a wasteful number, since it uses less digits than its factorization.

5491978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2745991.

The product of its digits is 90720, while the sum is 43.

The square root of 5491978 is about 2343.4969596737. The cubic root of 5491978 is about 176.4315554499.

The spelling of 5491978 in words is "five million, four hundred ninety-one thousand, nine hundred seventy-eight".