216778257619 has 16 divisors (see below), whose sum is σ = 270287769600. Its totient is φ = 168906389760.

The previous prime is 216778257613. The next prime is 216778257623. The reversal of 216778257619 is 916752877612.

It is a cyclic number.

It is not a de Polignac number, because 216778257619 - 2³ = 216778257611 is a prime.

It is a super-2 number, since 2×216778257619² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216778257611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1115022 + ... + 1294924.

It is an arithmetic number, because the mean of its divisors is an integer number (16892985600).

Almost surely, 2^216778257619 is an apocalyptic number.

216778257619 is a deficient number, since it is larger than the sum of its proper divisors (53509511981).

216778257619 is a wasteful number, since it uses less digits than its factorization.

216778257619 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195570.

The product of its digits is 17781120, while the sum is 61.

The spelling of 216778257619 in words is "two hundred sixteen billion, seven hundred seventy-eight million, two hundred fifty-seven thousand, six hundred nineteen".