211937774689 has 9 divisors (see below), whose sum is σ = 215497675731. Its totient is φ = 208435762920.

The previous prime is 211937774681. The next prime is 211937774693. The reversal of 211937774689 is 986477739112.

It is a happy number.

The square root of 211937774689 is 460367.

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., 6891822289 + 205045952400 = 83017^2 + 452820^2 .

It is not a de Polignac number, because 211937774689 - 2³ = 211937774681 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 211937774689.

It is not an unprimeable number, because it can be changed into a prime (211937774681) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 28078614 + ... + 28086160.

Almost surely, 2^211937774689 is an apocalyptic number.

211937774689 is the 460367-th square number.

211937774689 is the 230184-th centered octagonal number.

It is an amenable number.

211937774689 is a deficient number, since it is larger than the sum of its proper divisors (3559901042).

211937774689 is an frugal number, since it uses more digits than its factorization.

211937774689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15216 (or 7608 counting only the distinct ones).

The product of its digits is 32006016, while the sum is 64.

Multiplying 211937774689 by its sum of digits (64), we get a square (13564017580096 = 3682936²).

The spelling of 211937774689 in words is "two hundred eleven billion, nine hundred thirty-seven million, seven hundred seventy-four thousand, six hundred eighty-nine".