675917821 has 2 divisors, whose sum is σ = 675917822. Its totient is φ = 675917820.

The previous prime is 675917797. The next prime is 675917833. The reversal of 675917821 is 128719576.

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., 456463225 + 219454596 = 21365^2 + 14814^2 .

It is a cyclic number.

It is not a de Polignac number, because 675917821 - 2⁹ = 675917309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (675914821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 337958910 + 337958911.

It is an arithmetic number, because the mean of its divisors is an integer number (337958911).

Almost surely, 2^675917821 is an apocalyptic number.

It is an amenable number.

675917821 is a deficient number, since it is larger than the sum of its proper divisors (1).

675917821 is an equidigital number, since it uses as much as digits as its factorization.

675917821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 211680, while the sum is 46.

The square root of 675917821 is about 25998.4195865826. The cubic root of 675917821 is about 877.6027302665.

The spelling of 675917821 in words is "six hundred seventy-five million, nine hundred seventeen thousand, eight hundred twenty-one".