525278021 has 2 divisors, whose sum is σ = 525278022. Its totient is φ = 525278020.

The previous prime is 525277943. The next prime is 525278023. The reversal of 525278021 is 120872525.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 519201796 + 6076225 = 22786^2 + 2465^2 .

It is a cyclic number.

It is not a de Polignac number, because 525278021 - 2²⁶ = 458169157 is a prime.

It is a Sophie Germain prime.

Together with 525278023, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (525278023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 262639010 + 262639011.

It is an arithmetic number, because the mean of its divisors is an integer number (262639011).

Almost surely, 2^525278021 is an apocalyptic number.

It is an amenable number.

525278021 is a deficient number, since it is larger than the sum of its proper divisors (1).

525278021 is an equidigital number, since it uses as much as digits as its factorization.

525278021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11200, while the sum is 32.

The square root of 525278021 is about 22918.9445873932. The cubic root of 525278021 is about 806.8567001193.

The spelling of 525278021 in words is "five hundred twenty-five million, two hundred seventy-eight thousand, twenty-one".