209292381897481 has 3 divisors (see below), whose sum is σ = 209292396364423. Its totient is φ = 209292367430540.

The previous prime is 209292381897479. The next prime is 209292381897503. The reversal of 209292381897481 is 184798183292902.

The square root of 209292381897481 is 14466941.

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

209292381897481 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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., 116529671701881 + 92762710195600 = 10794891^2 + 9631340^2 .

It is not a de Polignac number, because 209292381897481 - 2¹ = 209292381897479 is a prime.

It is a super-3 number, since 3×209292381897481³ (a number of 44 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (209292381892481) 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, 7233471 + ... + 21700411.

Almost surely, 2^{209292381897481} is an apocalyptic number.

209292381897481 is the 14466941-st square number.

209292381897481 is the 7233471-st centered octagonal number.

It is an amenable number.

209292381897481 is a deficient number, since it is larger than the sum of its proper divisors (14466942).

209292381897481 is an frugal number, since it uses more digits than its factorization.

209292381897481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28933882 (or 14466941 counting only the distinct ones).

The product of its (nonzero) digits is 250822656, while the sum is 73.

The spelling of 209292381897481 in words is "two hundred nine trillion, two hundred ninety-two billion, three hundred eighty-one million, eight hundred ninety-seven thousand, four hundred eighty-one".