1549009421 has 2 divisors, whose sum is σ = 1549009422. Its totient is φ = 1549009420.

The previous prime is 1549009373. The next prime is 1549009453. The reversal of 1549009421 is 1249009451.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1392409225 + 156600196 = 37315^2 + 12514^2 .

It is a cyclic number.

It is not a de Polignac number, because 1549009421 - 2²² = 1544815117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1549009321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 774504710 + 774504711.

It is an arithmetic number, because the mean of its divisors is an integer number (774504711).

Almost surely, 2^1549009421 is an apocalyptic number.

It is an amenable number.

1549009421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1549009421 is an equidigital number, since it uses as much as digits as its factorization.

1549009421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 35.

The square root of 1549009421 is about 39357.4569935610. The cubic root of 1549009421 is about 1157.0479388854.

The spelling of 1549009421 in words is "one billion, five hundred forty-nine million, nine thousand, four hundred twenty-one".