670950821 has 2 divisors, whose sum is σ = 670950822. Its totient is φ = 670950820.

The previous prime is 670950809. The next prime is 670950823. The reversal of 670950821 is 128059076.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 479128321 + 191822500 = 21889^2 + 13850^2 .

It is a cyclic number.

It is not a de Polignac number, because 670950821 - 2¹⁴ = 670934437 is a prime.

It is a Sophie Germain prime.

Together with 670950823, 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 (670950823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 335475410 + 335475411.

It is an arithmetic number, because the mean of its divisors is an integer number (335475411).

Almost surely, 2^670950821 is an apocalyptic number.

It is an amenable number.

670950821 is a deficient number, since it is larger than the sum of its proper divisors (1).

670950821 is an equidigital number, since it uses as much as digits as its factorization.

670950821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 38.

The square root of 670950821 is about 25902.7184094643. The cubic root of 670950821 is about 875.4477473334.

The spelling of 670950821 in words is "six hundred seventy million, nine hundred fifty thousand, eight hundred twenty-one".