219219667681 has 27 divisors (see below), whose sum is σ = 257035773267. Its totient is φ = 186422095440.

The previous prime is 219219667661. The next prime is 219219667691. The reversal of 219219667681 is 186766912912.

The square root of 219219667681 is 468209.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 12271100625 + 206948567056 = 110775^2 + 454916^2 .

It is not a de Polignac number, because 219219667681 - 2⁷ = 219219667553 is a prime.

It is a super-2 number, since 2×219219667681² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (219219667621) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 691544535 + ... + 691544851.

Almost surely, 2^219219667681 is an apocalyptic number.

219219667681 is the 468209-th square number.

219219667681 is the 234105-th centered octagonal number.

It is an amenable number.

219219667681 is a deficient number, since it is larger than the sum of its proper divisors (37816105586).

219219667681 is an frugal number, since it uses more digits than its factorization.

219219667681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1070 (or 535 counting only the distinct ones).

The product of its digits is 3919104, while the sum is 58.

The spelling of 219219667681 in words is "two hundred nineteen billion, two hundred nineteen million, six hundred sixty-seven thousand, six hundred eighty-one".