891047266209 has 9 divisors (see below), whose sum is σ = 1287072363889. Its totient is φ = 594029622900.

The previous prime is 891047266199. The next prime is 891047266211. The reversal of 891047266209 is 902662740198.

The square root of 891047266209 is 943953.

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

891047266209 is a `hidden beast` number, since 8 + 9 + 1 + 0 + 4 + 7 + 2 + 6 + 620 + 9 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 891047266209 - 2¹¹ = 891047264161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (891047266009) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2674534 + ... + 2989184.

Almost surely, 2^891047266209 is an apocalyptic number.

891047266209 is the 943953-rd square number.

891047266209 is the 471977-th centered octagonal number.

It is an amenable number.

891047266209 is a deficient number, since it is larger than the sum of its proper divisors (396025097680).

891047266209 is an frugal number, since it uses more digits than its factorization.

891047266209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 629308 (or 314654 counting only the distinct ones).

The product of its (nonzero) digits is 2612736, while the sum is 54.

The spelling of 891047266209 in words is "eight hundred ninety-one billion, forty-seven million, two hundred sixty-six thousand, two hundred nine".