90922781 has 2 divisors, whose sum is σ = 90922782. Its totient is φ = 90922780.

The previous prime is 90922751. The next prime is 90922787. The reversal of 90922781 is 18722909.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 88548100 + 2374681 = 9410^2 + 1541^2 .

It is an emirp because it is prime and its reverse (18722909) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90922781 - 2¹⁴ = 90906397 is a prime.

It is a super-2 number, since 2×90922781² = 16533904209547922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90922787) 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, 45461390 + 45461391.

It is an arithmetic number, because the mean of its divisors is an integer number (45461391).

Almost surely, 2^90922781 is an apocalyptic number.

It is an amenable number.

90922781 is a deficient number, since it is larger than the sum of its proper divisors (1).

90922781 is an equidigital number, since it uses as much as digits as its factorization.

90922781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 90922781 is about 9535.3437798540. The cubic root of 90922781 is about 449.6668826853. Note that the first 3 decimals are identical.

The spelling of 90922781 in words is "ninety million, nine hundred twenty-two thousand, seven hundred eighty-one".