213771798757969 has 27 divisors (see below), whose sum is σ = 227055840024699. Its totient is φ = 201235558818240.

The previous prime is 213771798757927. The next prime is 213771798757991. The reversal of 213771798757969 is 969757897177312.

The square root of 213771798757969 is 14620937.

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., 115555770597969 + 98216028160000 = 10749687^2 + 9910400^2 .

It is not a de Polignac number, because 213771798757969 - 2²⁷ = 213771664540241 is a prime.

It is a super-2 number, since 2×213771798757969² (a number of 29 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 213771798757969.

It is not an unprimeable number, because it can be changed into a prime (213771798752969) 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, 45281039529 + ... + 45281044249.

Almost surely, 2^{213771798757969} is an apocalyptic number.

213771798757969 is the 14620937-th square number.

213771798757969 is the 7310469-th centered octagonal number.

It is an amenable number.

213771798757969 is a deficient number, since it is larger than the sum of its proper divisors (13284041266730).

213771798757969 is an frugal number, since it uses more digits than its factorization.

213771798757969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9806 (or 4903 counting only the distinct ones).

The product of its digits is 17643316320, while the sum is 88.

The spelling of 213771798757969 in words is "two hundred thirteen trillion, seven hundred seventy-one billion, seven hundred ninety-eight million, seven hundred fifty-seven thousand, nine hundred sixty-nine".