921604381 has 2 divisors, whose sum is σ = 921604382. Its totient is φ = 921604380.

The previous prime is 921604373. The next prime is 921604393. The reversal of 921604381 is 183406129.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 916272900 + 5331481 = 30270^2 + 2309^2 .

It is a cyclic number.

It is not a de Polignac number, because 921604381 - 2³ = 921604373 is a prime.

It is a super-2 number, since 2×921604381² = 1698709270156786322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (921604331) 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, 460802190 + 460802191.

It is an arithmetic number, because the mean of its divisors is an integer number (460802191).

Almost surely, 2^921604381 is an apocalyptic number.

It is an amenable number.

921604381 is a deficient number, since it is larger than the sum of its proper divisors (1).

921604381 is an equidigital number, since it uses as much as digits as its factorization.

921604381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 921604381 is about 30357.9376934600. The cubic root of 921604381 is about 973.1538613105.

The spelling of 921604381 in words is "nine hundred twenty-one million, six hundred four thousand, three hundred eighty-one".