891321025 has 27 divisors (see below), whose sum is σ = 1287194121. Its totient is φ = 610475040.

The previous prime is 891320993. The next prime is 891321049. The reversal of 891321025 is 520123198.

The square root of 891321025 is 29855.

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

It can be written as a sum of positive squares in 4 ways, for example, as 356416641 + 534904384 = 18879^2 + 23128^2 .

It is not a de Polignac number, because 891321025 - 2⁵ = 891320993 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1044499 + ... + 1045351.

Almost surely, 2^891321025 is an apocalyptic number.

891321025 is the 29855-th square number.

891321025 is the 14928-th centered octagonal number.

It is an amenable number.

891321025 is a deficient number, since it is larger than the sum of its proper divisors (395873096).

891321025 is an frugal number, since it uses more digits than its factorization.

891321025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1730 (or 865 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 31.

The cubic root of 891321025 is about 962.3758517560.

The spelling of 891321025 in words is "eight hundred ninety-one million, three hundred twenty-one thousand, twenty-five".