5781978 has 12 divisors (see below), whose sum is σ = 12527658. Its totient is φ = 1927320.

The previous prime is 5781977. The next prime is 5782001. The reversal of 5781978 is 8791875.

5781978 is a `hidden beast` number, since 578 + 1 + 9 + 78 = 666.

It can be written as a sum of positive squares in only one way, i.e., 5774409 + 7569 = 2403^2 + 87^2 .

It is not an unprimeable number, because it can be changed into a prime (5781977) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 160593 + ... + 160628.

Almost surely, 2^5781978 is an apocalyptic number.

5781978 is an abundant number, since it is smaller than the sum of its proper divisors (6745680).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

5781978 is a wasteful number, since it uses less digits than its factorization.

5781978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321229 (or 321226 counting only the distinct ones).

The product of its digits is 141120, while the sum is 45.

The square root of 5781978 is about 2404.5743906147. The cubic root of 5781978 is about 179.4838919653.

It can be divided in two parts, 578 and 1978, that added together give a triangular number (2556 = T₇₁).

The spelling of 5781978 in words is "five million, seven hundred eighty-one thousand, nine hundred seventy-eight".