525816821 has 2 divisors, whose sum is σ = 525816822. Its totient is φ = 525816820.

The previous prime is 525816799. The next prime is 525816833. The reversal of 525816821 is 128618525.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 515925796 + 9891025 = 22714^2 + 3145^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-525816821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (525815821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 262908410 + 262908411.

It is an arithmetic number, because the mean of its divisors is an integer number (262908411).

Almost surely, 2^525816821 is an apocalyptic number.

It is an amenable number.

525816821 is a deficient number, since it is larger than the sum of its proper divisors (1).

525816821 is an equidigital number, since it uses as much as digits as its factorization.

525816821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38400, while the sum is 38.

The square root of 525816821 is about 22930.6960426412. The cubic root of 525816821 is about 807.1324815884.

The spelling of 525816821 in words is "five hundred twenty-five million, eight hundred sixteen thousand, eight hundred twenty-one".