219856894321 has 3 divisors (see below), whose sum is σ = 219857363211. Its totient is φ = 219856425432.

The previous prime is 219856894307. The next prime is 219856894379. The reversal of 219856894321 is 123498658912.

It is a happy number.

The square root of 219856894321 is 468889.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 73137252721 + 146719641600 = 270439^2 + 383040^2 .

It is not a de Polignac number, because 219856894321 - 2²³ = 219848505713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (219856894391) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 234445 + ... + 703333.

It is an arithmetic number, because the mean of its divisors is an integer number (73285787737).

Almost surely, 2^219856894321 is an apocalyptic number.

219856894321 is the 468889-th square number.

219856894321 is the 234445-th centered octagonal number.

It is an amenable number.

219856894321 is a deficient number, since it is larger than the sum of its proper divisors (468890).

219856894321 is an frugal number, since it uses more digits than its factorization.

219856894321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 937778 (or 468889 counting only the distinct ones).

The product of its digits is 7464960, while the sum is 58.

The spelling of 219856894321 in words is "two hundred nineteen billion, eight hundred fifty-six million, eight hundred ninety-four thousand, three hundred twenty-one".