90136381 has 2 divisors, whose sum is σ = 90136382. Its totient is φ = 90136380.

The previous prime is 90136337. The next prime is 90136391. The reversal of 90136381 is 18363109.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 70476025 + 19660356 = 8395^2 + 4434^2 .

It is an emirp because it is prime and its reverse (18363109) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90136381 - 2¹¹ = 90134333 is a prime.

It is a super-2 number, since 2×90136381² = 16249134359554322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (90136331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45068190 + 45068191.

It is an arithmetic number, because the mean of its divisors is an integer number (45068191).

Almost surely, 2^90136381 is an apocalyptic number.

It is an amenable number.

90136381 is a deficient number, since it is larger than the sum of its proper divisors (1).

90136381 is an equidigital number, since it uses as much as digits as its factorization.

90136381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 90136381 is about 9494.0181693527. The cubic root of 90136381 is about 448.3667228057.

The spelling of 90136381 in words is "ninety million, one hundred thirty-six thousand, three hundred eighty-one".