516406778 has 4 divisors (see below), whose sum is σ = 774610170. Its totient is φ = 258203388.

The previous prime is 516406771. The next prime is 516406783. The reversal of 516406778 is 877604615.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 877604615 = 5 ⋅175520923.

It can be written as a sum of positive squares in only one way, i.e., 461691169 + 54715609 = 21487^2 + 7397^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (516406771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 129101693 + ... + 129101696.

Almost surely, 2^516406778 is an apocalyptic number.

516406778 is a deficient number, since it is larger than the sum of its proper divisors (258203392).

516406778 is a wasteful number, since it uses less digits than its factorization.

516406778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258203391.

The product of its (nonzero) digits is 282240, while the sum is 44.

The square root of 516406778 is about 22724.5853207490. The cubic root of 516406778 is about 802.2886432714.

The spelling of 516406778 in words is "five hundred sixteen million, four hundred six thousand, seven hundred seventy-eight".