90989749 has 2 divisors, whose sum is σ = 90989750. Its totient is φ = 90989748.

The previous prime is 90989737. The next prime is 90989777. The reversal of 90989749 is 94798909.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77616100 + 13373649 = 8810^2 + 3657^2 .

It is an emirp because it is prime and its reverse (94798909) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90989749 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 90989749.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90981749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45494874 + 45494875.

It is an arithmetic number, because the mean of its divisors is an integer number (45494875).

Almost surely, 2^90989749 is an apocalyptic number.

It is an amenable number.

90989749 is a deficient number, since it is larger than the sum of its proper divisors (1).

90989749 is an equidigital number, since it uses as much as digits as its factorization.

90989749 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1469664, while the sum is 55.

The square root of 90989749 is about 9538.8547006441. The cubic root of 90989749 is about 449.7772543703. Note that the first 3 decimals are identical.

The spelling of 90989749 in words is "ninety million, nine hundred eighty-nine thousand, seven hundred forty-nine".