821525 has 12 divisors (see below), whose sum is σ = 1079172. Its totient is φ = 618240.

The previous prime is 821519. The next prime is 821551. The reversal of 821525 is 525128.

It can be written as a sum of positive squares in 6 ways, for example, as 7921 + 813604 = 89^2 + 902^2 .

It is not a de Polignac number, because 821525 - 2⁶ = 821461 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 821525.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 542 + ... + 1391.

It is an arithmetic number, because the mean of its divisors is an integer number (89931).

2⁸²¹⁵²⁵ is an apocalyptic number.

821525 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

821525 is a deficient number, since it is larger than the sum of its proper divisors (257647).

821525 is a wasteful number, since it uses less digits than its factorization.

821525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1960 (or 1955 counting only the distinct ones).

The product of its digits is 800, while the sum is 23.

The square root of 821525 is about 906.3801630662. The cubic root of 821525 is about 93.6570040789.

The spelling of 821525 in words is "eight hundred twenty-one thousand, five hundred twenty-five".