209864369231 has 4 divisors (see below), whose sum is σ = 228942948264. Its totient is φ = 190785790200.

The previous prime is 209864369227. The next prime is 209864369233. The reversal of 209864369231 is 132963468902.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 209864369231 - 2² = 209864369227 is a prime.

It is a super-2 number, since 2×209864369231² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209864369233) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9539289500 + ... + 9539289521.

It is an arithmetic number, because the mean of its divisors is an integer number (57235737066).

Almost surely, 2^209864369231 is an apocalyptic number.

209864369231 is a deficient number, since it is larger than the sum of its proper divisors (19078579033).

209864369231 is a wasteful number, since it uses less digits than its factorization.

209864369231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19078579032.

The product of its (nonzero) digits is 3359232, while the sum is 53.

The spelling of 209864369231 in words is "two hundred nine billion, eight hundred sixty-four million, three hundred sixty-nine thousand, two hundred thirty-one".