904166621 has 2 divisors, whose sum is σ = 904166622. Its totient is φ = 904166620.

The previous prime is 904166609. The next prime is 904166647. The reversal of 904166621 is 126661409.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 665124100 + 239042521 = 25790^2 + 15461^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-904166621 is a prime.

It is a Sophie Germain prime.

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 (904166821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 452083310 + 452083311.

It is an arithmetic number, because the mean of its divisors is an integer number (452083311).

Almost surely, 2^904166621 is an apocalyptic number.

It is an amenable number.

904166621 is a deficient number, since it is larger than the sum of its proper divisors (1).

904166621 is an equidigital number, since it uses as much as digits as its factorization.

904166621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 904166621 is about 30069.3634950925. The cubic root of 904166621 is about 966.9770276658.

The spelling of 904166621 in words is "nine hundred four million, one hundred sixty-six thousand, six hundred twenty-one".