90638549 has 2 divisors, whose sum is σ = 90638550. Its totient is φ = 90638548.

The previous prime is 90638521. The next prime is 90638551. The reversal of 90638549 is 94583609.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 90592324 + 46225 = 9518^2 + 215^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90638549 is a prime.

Together with 90638551, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90631549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45319274 + 45319275.

It is an arithmetic number, because the mean of its divisors is an integer number (45319275).

Almost surely, 2^90638549 is an apocalyptic number.

It is an amenable number.

90638549 is a deficient number, since it is larger than the sum of its proper divisors (1).

90638549 is an equidigital number, since it uses as much as digits as its factorization.

90638549 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 233280, while the sum is 44.

The square root of 90638549 is about 9520.4279840772. The cubic root of 90638549 is about 449.1978285093.

The spelling of 90638549 in words is "ninety million, six hundred thirty-eight thousand, five hundred forty-nine".