90184781 has 2 divisors, whose sum is σ = 90184782. Its totient is φ = 90184780.

The previous prime is 90184777. The next prime is 90184883. The reversal of 90184781 is 18748109.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78039556 + 12145225 = 8834^2 + 3485^2 .

It is a cyclic number.

It is not a de Polignac number, because 90184781 - 2² = 90184777 is a prime.

It is a super-2 number, since 2×90184781² = 16266589448035922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90184181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45092390 + 45092391.

It is an arithmetic number, because the mean of its divisors is an integer number (45092391).

Almost surely, 2^90184781 is an apocalyptic number.

It is an amenable number.

90184781 is a deficient number, since it is larger than the sum of its proper divisors (1).

90184781 is an equidigital number, since it uses as much as digits as its factorization.

90184781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16128, while the sum is 38.

The square root of 90184781 is about 9496.5668006917. The cubic root of 90184781 is about 448.4469607226.

The spelling of 90184781 in words is "ninety million, one hundred eighty-four thousand, seven hundred eighty-one".