209913902897 has 6 divisors (see below), whose sum is σ = 222263779734. Its totient is φ = 197564248320.

The previous prime is 209913902837. The next prime is 209913902923. The reversal of 209913902897 is 798209319902.

It can be written as a sum of positive squares in 3 ways, for example, as 64843566736 + 145070336161 = 254644^2 + 380881^2 .

It is not a de Polignac number, because 209913902897 - 2⁶ = 209913902833 is a prime.

It is a super-2 number, since 2×209913902897² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (209913902837) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1833497 + ... + 1944617.

It is an arithmetic number, because the mean of its divisors is an integer number (37043963289).

Almost surely, 2^209913902897 is an apocalyptic number.

It is an amenable number.

209913902897 is a deficient number, since it is larger than the sum of its proper divisors (12349876837).

209913902897 is an frugal number, since it uses more digits than its factorization.

209913902897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222259 (or 111138 counting only the distinct ones).

The product of its (nonzero) digits is 4408992, while the sum is 59.

The spelling of 209913902897 in words is "two hundred nine billion, nine hundred thirteen million, nine hundred two thousand, eight hundred ninety-seven".