209806660512 has 96 divisors (see below), whose sum is σ = 618812006400. Its totient is φ = 69149735424.

The previous prime is 209806660489. The next prime is 209806660517. The reversal of 209806660512 is 215066608902.

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (209806660517) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1287328 + ... + 1441119.

It is an arithmetic number, because the mean of its divisors is an integer number (6445958400).

Almost surely, 2^209806660512 is an apocalyptic number.

It is an amenable number.

209806660512 is an abundant number, since it is smaller than the sum of its proper divisors (409005345888).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

209806660512 is a wasteful number, since it uses less digits than its factorization.

209806660512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2728555 (or 2728541 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The spelling of 209806660512 in words is "two hundred nine billion, eight hundred six million, six hundred sixty thousand, five hundred twelve".