90821749 has 2 divisors, whose sum is σ = 90821750. Its totient is φ = 90821748.

The previous prime is 90821737. The next prime is 90821761. The reversal of 90821749 is 94712809.

It is a balanced prime because it is at equal distance from previous prime (90821737) and next prime (90821761).

It can be written as a sum of positive squares in only one way, i.e., 55502500 + 35319249 = 7450^2 + 5943^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90821749 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90821789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45410874 + 45410875.

It is an arithmetic number, because the mean of its divisors is an integer number (45410875).

Almost surely, 2^90821749 is an apocalyptic number.

It is an amenable number.

90821749 is a deficient number, since it is larger than the sum of its proper divisors (1).

90821749 is an equidigital number, since it uses as much as digits as its factorization.

90821749 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 90821749 is about 9530.0445434426. The cubic root of 90821749 is about 449.5002666414.

The spelling of 90821749 in words is "ninety million, eight hundred twenty-one thousand, seven hundred forty-nine".