891881916025 has 27 divisors (see below), whose sum is σ = 1167321559053. Its totient is φ = 675884613600.

The previous prime is 891881915993. The next prime is 891881916043. The reversal of 891881916025 is 520619188198.

The square root of 891881916025 is 944395.

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

891881916025 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 558611244409 + 333270671616 = 747403^2 + 577296^2 .

It is not a de Polignac number, because 891881916025 - 2⁵ = 891881915993 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 89712555 + ... + 89722495.

Almost surely, 2^891881916025 is an apocalyptic number.

891881916025 is the 944395-th square number.

891881916025 is the 472198-th centered octagonal number.

It is an amenable number.

891881916025 is a deficient number, since it is larger than the sum of its proper divisors (275439643028).

891881916025 is an frugal number, since it uses more digits than its factorization.

891881916025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19930 (or 9965 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 58.

The spelling of 891881916025 in words is "eight hundred ninety-one billion, eight hundred eighty-one million, nine hundred sixteen thousand, twenty-five".