209015855772 has 12 divisors (see below), whose sum is σ = 487703663496. Its totient is φ = 69671951920.

The previous prime is 209015855761. The next prime is 209015855821. The reversal of 209015855772 is 277558510902.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8708993979 + ... + 8708994002.

It is an arithmetic number, because the mean of its divisors is an integer number (40641971958).

Almost surely, 2^209015855772 is an apocalyptic number.

It is an amenable number.

209015855772 is an abundant number, since it is smaller than the sum of its proper divisors (278687807724).

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

209015855772 is a wasteful number, since it uses less digits than its factorization.

209015855772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17417987988 (or 17417987986 counting only the distinct ones).

The product of its (nonzero) digits is 1764000, while the sum is 51.

The spelling of 209015855772 in words is "two hundred nine billion, fifteen million, eight hundred fifty-five thousand, seven hundred seventy-two".