821725 has 6 divisors (see below), whose sum is σ = 1018970. Its totient is φ = 657360.

The previous prime is 821677. The next prime is 821741. The reversal of 821725 is 527128.

It can be written as a sum of positive squares in 3 ways, for example, as 66564 + 755161 = 258^2 + 869^2 .

It is a de Polignac number, because none of the positive numbers 2^k-821725 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25), and also a Moran number because the ratio is a prime number: 32869 = 821725 / (8 + 2 + 1 + 7 + 2 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 821725.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 16410 + ... + 16459.

2⁸²¹⁷²⁵ is an apocalyptic number.

It is an amenable number.

821725 is a deficient number, since it is larger than the sum of its proper divisors (197245).

821725 is a wasteful number, since it uses less digits than its factorization.

821725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32879 (or 32874 counting only the distinct ones).

The product of its digits is 1120, while the sum is 25.

The square root of 821725 is about 906.4904853334. The cubic root of 821725 is about 93.6646037182.

The spelling of 821725 in words is "eight hundred twenty-one thousand, seven hundred twenty-five".