90220981 has 2 divisors, whose sum is σ = 90220982. Its totient is φ = 90220980.

The previous prime is 90220969. The next prime is 90221003. The reversal of 90220981 is 18902209.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66161956 + 24059025 = 8134^2 + 4905^2 .

It is a cyclic number.

It is not a de Polignac number, because 90220981 - 2¹³ = 90212789 is a prime.

It is a super-2 number, since 2×90220981² = 16279650825204722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90220181) 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, 45110490 + 45110491.

It is an arithmetic number, because the mean of its divisors is an integer number (45110491).

Almost surely, 2^90220981 is an apocalyptic number.

It is an amenable number.

90220981 is a deficient number, since it is larger than the sum of its proper divisors (1).

90220981 is an equidigital number, since it uses as much as digits as its factorization.

90220981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 90220981 is about 9498.4725614174. The cubic root of 90220981 is about 448.5069546159.

The spelling of 90220981 in words is "ninety million, two hundred twenty thousand, nine hundred eighty-one".